In an attempt to evaluate health experiences of operating room personnel using previously published reports, the authors calculated summary relative risks (RRs) for each outcome under investigation by combining data from six studies. For each summary RR, they also calculated 95% confidence limits; when the range of the confidence interval excludes 1.0, the increased risk is statistically significant at the 0.05 level. The most consistent evidence was for spontaneous abortion among pregnant physicians and nurses who work in operating rooms, where the RR was 1.3 (95% confidence limits from 1.2 to 1.4). For liver disease there were statistically significant increased RRs among both men (1.6, 1.3-1.9) and women (1.5, 1.2-1.9), but these were based on smaller numbers of studies. Although the results of pooled analyses are suggestive, most studies of this issue have relied on voluntary responses and self-reported outcomes, so that response and/or recall bias could explain these findings. In addition, these investigations generally have examined working in operating rooms rather than actual exposure to anesthetic gases. Finally, there have been considerable improvements in operating room scavenging systems during the last decade. Thus, prospective cohort studies are needed to determine whether there is a relationship between current levels of occupational exposure to anesthetic gases and adverse outcomes, particularly spontaneous abortion and liver disease.