A method was developed for measuring how different water flow rates from nipple drinkers affect the actual rates of water intake and spillage by pigs. A combination of video and electronic techniques provided simultaneous monitoring, during a drinking episode, of the flow rate of water through the nipple drinker and the accumulated weight of spilled water. These data yielded the actual water intake rate of the animal by subtraction. The method was used with 10 lactating sows drinking from bit nipples with eight different nominal flow rates ranging from 0.6 to 3.0 L/min. In the first 2 minutes of drinking, thirsty sows had intake rates averaging 2.17 L/min (for the five fastest drinking sows) or 1.58 L/min (for the five slowest) at the maximum nipple flow rate of 3.0 L/min. Later in the drinking episode, when motivation to drink was presumably less strong, increases in nipple flow rate above 1.8 L/min resulted in increased spillage but no increase in actual intake. The results suggest a 1.8 L/min flow rate to be ample for lactating sows using this delivery system when water is continuously available. The method should provide a basis for developing appropriate recommendations for different water delivery systems and different classes of pigs.