The effects of terbutaline on the mother and fetus were evaluated in 8 near-term pregnant baboons [Papio hybrid]. Significant suppression of postoperative spontaneous and oxytocin-augmented uterine activity was achieved with infusion rates of 0.36 and 0.56 .mu.g/kg per min, respectively. Maternal and fetal blood pressure and acid-base states as well as fetal heart rate were unaffected by administration of terbutaline to the mother, but mild maternal tachycardia was observed. Maternal and fetal blood glucose increased during terbutaline infusion. Direct administration of terbutaline to the fetus did not alter the fetal cardiovascular or acid-base state. In the baboon, terbutaline is an effective tocolytic agent with minimal untoward effects on mother or fetus.