To compare tolerability and tocolytic outcome between i.v. infused plant extract, Bryophyllum pinnatum, and beta-agonists. Study design: In a retrospective study, 67 pairs of pregnant women in preterm labor treated with intravenous B. pinnatum or beta-agonists were closely matched for maternal age, gestational age at tocolysis, CTG recorded contractions, cervical effacement, preterm premature rupture of the membranes, and history of preterm labor. Endpoints were prolongation of pregnancy, gestational age at delivery, pre-and postpartum duration of hospitalization, maternal tolerability, neonatal outcome and morbidity. Results: Pregnant women with B. pinnatumand beta-agonistswere equal in the prolongation of pregnancy (6.2 versus 5.4 days, NS), the gestaional age at delivery (38.0 versus 37.1 weeks, NS) and the duration of hospitalisations, but had less adverse effects (34.3 versus 55.2% with palpitation or dyspnea, P = 0.02). The neonatal outcome and morbidity in the B. pinnatum group were equal or better (oxygen use 10.4 versus 44.8% , P < 0.001; respiratory distress syndrome 4.5 versus 19.4% , P = 0.01). Conclusion: In the management of preterm labor B. pinnatum is no less effective than beta-agonists, but is significantly better tolerated. To compare tolerability and tocolytic outcome between iv infused plant extract, Bryophyllum pinnatum, and beta-agonists. Study design: In a retrospective study, 67 pairs of pregnant women in preterm labor treated with intravenous B. pinnatum or beta-agonists were closely matched for maternal age, gestational age at tocolysis, CTG recorded contractions, cervical effacement, preterm premature rupture of the membranes, and history of preterm labor. Endpoints were prolongation of pregnancy, gestational age at delivery, pre-and postpartum duration of hospitalization, maternal tolerability, neonatal outcome and morbidity. Results: Pregnant women with B. pinnatumand beta-agonists equal in the prolongation of pregnancy (6.2 versus 5.4 days, NS), the gestaional age at delivery (38.0 versus 37.1 weeks, NS) and the duration of hospitalizations, but had less adverse effects (34.3 versus 55.2% with palpitation or dyspnea, P = 0.02). The neonatal outcome and morbidity in the B. pinnatum group were equal or better (oxygen use 10.4 versus 44.8%, P <0.001; respiratory distress syndrome 4.5 versus 19.4%, P = 0.01). Conclusion: In the management of preterm labor B. pinnatum is no less effective than beta-agonists, but is significantly better tolerated.