The contractibility and trainability of the pelvic floor were investigated during pregnancy and after vaginal delivery in 86 healthy primiparae. One group (TG) (n = 38) was instructed in training the pelvic floor from the 33rd week of pregnancy, whereas the other group (non-TG) (n = 39) was not. Both groups were measured by perineometry five times between 33rd-39th week of pregnancy and approximately 8 weeks after delivery. Half of the women were also measured 8 months post partum. At the beginning of the study both groups showed the same strength of the pelvic floor. 8 weeks and 8 months after delivery the TG were significantly (p less than 0.05) better able to contract the pelvic floor compared with the non-TG. 8 months post partum, the TG had regained the initial values of pelvic floor contraction as from 33rd week of pregnancy, whereas the non-TG had not. During pregnancy there was a better ability to contract the pelvic floor in the TG vis-à-vis the non-TG, though not significantly so. No difference in the course of delivery was observed, and the frequency of complications was the same in the two groups.