ABSTRACT: Background: Showers and tubs in labor were not generally used in our center: When three whirlpool baths (Jacuzzis) were ordered as part of our renovations, a randomized, controlled trial was initiated to explore their effects on narcotic and epidural requirements. Methods: This study employed an intent-to-treat design, and the sample size was estimated to account for the fact that some women would be unable to use the tub. The experimental group of 393 women was offered the tub during labor and the control group of 392 women received conventional care. Results: No births occurred in the tub. The tub group required fewer pharmacologic agents than controls (66% vs 59%, p = 0.06), experienced fewer deliveries by forceps and vacuum (p = 0.019), and were more likely to have an intact perineum than the standard-care group (p = 0.019). Labor was longer for the tub group (p = 0.003), who coincidentally were more primiparous and in earlier labor on admission. No differences were noted in the low rates of maternal and newborn signs of infection in women with ruptured membranes. A subset of mothers expressed satisfaction with the tub experience and labor support. The cesarean rate among both groups was lower (8.9%) than our overall rate (16.6%) during the study period. Conclusions: Whirlpool baths in labor have positive effects on analgesia requirements, instrumentation rates, condition of the perineum, and personal satisfaction. Further study of the effects on labor length, pain, influence of labor support, and psychological outcomes is being planned.