Fetal heart rate (FHR) acceleration was evaluated in 1570 oxytocin challenge test (OCT) results, which were performed on 565 high-risk [human] patients. In positive OCT a significant decrease or lack of FHR acceleration was noted. Fetuses with positive OCT and lack of FHR acceleration were more compromised than those with better FHR acceleration. Negative OCT were associated with a good FHR acceleration approximately 95% of the time. Study of FHR acceleration in suspicious OCT were helpful in determining the significance and prognosis of a suspicious OCT.