Opinion of the Court

December 15, 1997

Chief Justice Rehnquist delivered the opinion of the Court.

We granted certiorari in this case to determine what standard an appellate court should apply in reviewing a trial court’s decision to admit or exclude expert testimony under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). We hold that abuse of discretion is the appropriate standard. We apply this standard and conclude that the District Court in this case did not abuse its discretion when it excluded certain proffered expert testimony.


Respondent Robert Joiner began work as an electrician in the Water & Light Department of Thomasville, Georgia (City) in 1973. This job required him to work with and around the City’s electrical transformers, which used a mineral-based dielectric fluid as a coolant. Joiner often had to stick his hands and arms into the fluid to make repairs. The fluid would sometimes splash onto him, occasionally getting into his eyes and mouth. In 1983 the City discovered that the fluid in some of the transformers was contaminated with polychlorinated biphenyls (PCBs). PCBs are widely considered to be hazardous to human health. Congress, with limited exceptions, banned the production and sale of PCBs in 1978. See 90 Stat. 2020, 15 U.S.C. § 2605(e)(2)(A). 

Joiner was diagnosed with small cell lung cancer in 1991. He1 sued petitioners in Georgia state court the following year. Petitioner Monsanto manufactured PCBs from 1935 to 1977; petitioners General Electric and Westinghouse Electric manufactured transformers and dielectric fluid. In his complaint Joiner linked his development of cancer to his exposure to PCBs and their derivatives, polychlorinated dibenzofurans (furans) and polychlorinated dibenzodioxins (dioxins). Joiner had been a smoker for approximately eight years, his parents had both been smokers, and there was a history of lung cancer in his family. He was thus perhaps already at a heightened risk of developing lung cancer eventually. The suit alleged that his exposure to PCBs “promoted” his cancer; had it not been for his exposure to these substances, his cancer would not have developed for many years, if at all.

Petitioners removed the case to federal court. Once there, they moved for summary judgment. They contended that (1) there was no evidence that Joiner suffered significant exposure to PCBs, furans, or dioxins, and (2) there was no admissible scientific evidence that PCBs promoted Joiner’s cancer. Joiner responded that there were numerous disputed factual issues that required resolution by a jury. He relied largely on the testimony of expert witnesses. In depositions, his experts had testified that PCBs alone can promote cancer and that furans and dioxins can also promote cancer. They opined that since Joiner had been exposed to PCBs, furans, and dioxins, such exposure was likely responsible for Joiner’s cancer.

The District Court ruled that there was a genuine issue of material fact as to whether Joiner had been exposed to PCBs. But it nevertheless granted summary judgment for petitioners because (1) there was no genuine issue as to whether Joiner had been exposed to furans and dioxins, and (2) the testimony of Joiner’s experts had failed to show that there was a link between exposure to PCBs and small cell lung cancer. The court believed that the testimony of respondent’s experts to the contrary did not rise above “subjective belief or unsupported speculation.” 864 F. Supp. 1310, 1329 (ND Ga. 1994). Their testimony was therefore inadmissible.

The Court of Appeals for the Eleventh Circuit reversed. 78 F.3d 524 (1996). It held that “[b]ecause the Federal Rules of Evidence governing expert testimony display a preference for admissibility, we apply a particularly stringent standard of review to the trial judge’s exclusion of expert testimony.” Id. at 529. Applying that standard, the Court of Appeals held that the District Court had erred in excluding the testimony of Joiner’s expert witnesses. The District Court had made two fundamental errors. First, it excluded the experts’ testimony because it “drew different conclusions from the research than did each of the experts.” The Court of Appeals opined that a district court should limit its role to determining the “legal reliability of proffered expert testimony, leaving the jury to decide the correctness of competing expert opinions.” Id. at 533. Second, the District Court had held that there was no genuine issue of material fact as to whether Joiner had been exposed to furans and dioxins. This was also incorrect, said the Court of Appeals, because testimony in the record supported the proposition that there had been such exposure.

We granted petitioners’ petition for a writ of certiorari, 520 U.S. _____ (1997), and we now reverse.


Petitioners challenge the standard applied by the Court of Appeals in reviewing the District Court’s decision to exclude respondent’s experts’ proffered testimony. They argue that that court should have applied traditional “abuse of discretion” review. Respondent agrees that abuse of discretion is the correct standard of review. He contends, however, that the Court of Appeals applied an abuse of discretion standard in this case. As he reads it, the phrase “particularly stringent” announced no new standard of review. It was simply an acknowledgement that an appellate court can and will devote more resources to analyzing district court decisions that are dispositive of the entire litigation. All evidentiary decisions are reviewed under an abuse of discretion standard. He argues, however, that it is perfectly reasonable for appellate courts to give particular attention to those decisions that are outcome-determinative.

We have held that abuse of discretion is the proper standard of review of a district court’s evidentiary rulings. Old Chief v. United States, 519 U.S. ____, ____ n. 1 (1997) (slip op., at 1—2, n.1), United States v. Abel, 469 U.S. 45, 54 (1984). Indeed, our cases on the subject go back as far as Spring Co. v. Edgar, 99 U.S. 645, 658 (1879) where we said that “cases arise where it is very much a matter of discretion with the court whether to receive or exclude the evidence; but the appellate court will not reverse in such a case, unless the ruling is manifestly erroneous.” The Court of Appeals suggested that Daubert somehow altered this general rule in the context of a district court’s decision to exclude scientific evidence. But Daubert did not address the standard of appellate review for evidentiary rulings at all. It did hold that the “austere” Frye standard of “general acceptance” had not been carried over into the Federal Rules of Evidence. But the opinion also said:

“That the Frye test was displaced by the Rules of Evidence does not mean, however, that the Rules themselves place no limits on the admissibility of purportedly scientific evidence. Nor is the trial judge disabled from screening such evidence. To the contrary, under the Rules the trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable.” 509 U.S., at 589 (footnote omitted).  Next Page ->


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