Maternal tobacco use is associated with a significant reduction in the risk of preeclampsia (PE). Secondhand Smoke Exposure (SHSE), also known as “passive” smoking, has been associated with similar adverse effects as that of active smoking, such as decreased birthweight and delayed infant neurodevelopment. Yet studies evaluating whether SHSE is also associated with a reduction in the risk of PE have yielded inconsistent results. We performed a retrospective analysis of a prospective, population-based cohort (2011-2020) from our institutional database. Maternal demographics, comorbidities, and substance use (inclusive of direct query of SHSE, active smoking, and duration and extent of use in their native language) were uniformly collected for all subjects. Subjects with singleton pregnancies were classified as never or ever exposed to tobacco. Those exposed were further categorized as having active use, use prior to pregnancy, or current SHSPE. Each category of smoke exposure was compared to the reference, never smoking group. Univariate analysis was performed using Chi-Square and ANOVA. Logistic regression was used to control for confounders identified in univariate analysis. Among a cohort of 40,548 subjects, we identified 521 (1.6%) active smokers, 3,926 (12%) prior smokers, 1,269 (3.9%) SHSE, and 27,079 (82.6%) never smokers (reference). After adjusting for confounders, SHSE had a 40% reduction in the odds of developing preeclampsia (aOR 0.60, 95% CI 0.40-0.86). There was no difference in the odds of preeclampsia for active smokers (aOR 1.50, 95% CI 0.96-2.23) or prior smokers (aOR 0.91, 95% CI 0.75-1.09). SHSE was associated with a significant reduction in the odds of preeclampsia, which is consistent with findings from previous studies that suggest SHS is also associated with similar risks in pregnancy to that of active maternal tobacco use. We did not see a decreased incidence of preeclampsia for active smokers, and we speculate that this may be due to underpowering to identify this association as less than 2% of our cohort identified as active smokers.