We studied the prevalence and relationship of stress and working conditions with adverse reproductive outcomes in a cohort of female US law-school alumnae. A total of 584 female lawyers (74% response), aged 25 to 63, responded to a mailed questionnaire. Job hours per week was a strong predictor of job stress. In a logistic regression analysis, women working > 45 hours/week were five times as likely to report high stress as those working < 35 hours/week. Marriage and length of time on the job showed a small inverse association with stress. Women who worked more than 45 hours/week during their first trimester of pregnancy were more likely to report high stress at work during pregnancy. After being adjusted for confounding factors, weekly job hours during the first trimester of pregnancy showed a strong independent association with spontaneous abortion risk (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.4 to 6.6). Seven or more alcohol drinks/week was also independently associated with spontaneous abortion risk (OR, 4.8; 95% CI, 1.5 to 18.1). Self-reported stress during pregnancy was positively but not statistically significantly associated with spontaneous abortion (OR, 1.4; 95% CI 0.8 to 2.3).