The objectives of the study were to assess the prevalence of urinary incontinence symptoms during pregnancy in a racially mixed sample and to identify potential predisposing variables. Five hundred and twenty-three women were interviewed in the hospital on postpartum day 2 or 3 and by telephone at 6-week follow-up. A significantly larger proportion of white women reported accidental loss of urine than did black women (62.6% vs. 46.4%;P<0.01). A breakdown by type of incontinence indicated that the race effect was largely attributable to the significantly higher prevalence of the symptom of stress incontinence among white women (P<0.0001). In stepwise logistic regression modeling, previous incontinence, education level, parity and nocturia were selected as the strongest predictors of incontinence in white women. Attendance at childbirth classes was the only predictor of incontinence for black women. The results raise the possibility that higher rates of incontinence among white women might be due to differences in the pelvic floor.