The objectives were to evaluate the effects of treatment of dairy cows with recombinant bovine somatotropin (rbST) during the periparturient period on health and production. Holstein (HO, n = 302) and Jersey (JS, n = 522) cows were enrolled in the experiment 21 d before calving. Cows were assigned randomly to the control and rbST (125 mg of rbST every 7 d from −21 to 21 d relative to calving) treatments. At −21, 0, 30, and 60 d relative to calving, BCS was recorded. Occurrence of retained placenta (RP) was recorded and cows were examined for diagnosis of metritis 4, 7, 10, and 14 d postpartum (DIM). Acute metritis (metritis and fever and/or anorexia) was recorded in the JS herd. Blood was sampled 7 and 14 d postpartum to determine ketosis incidence. Cows were milked thrice daily. In the HO herd, milk yield and composition were determined weekly until 21 d postpartum; thereafter, monthly milk yield was recorded. In the JS herd, milk yield and composition were recorded monthly. Dichotomous data were analyzed by logistic regression and continuous data were analyzed by ANOVA. Incidence of RP tended to be affected by treatment (HO-control = 14.4%, rbST = 6.1%; JS-control = 1.5%, rbST = 1.2%; P = 0.10). Incidence of metritis was reduced by rbST treatment (HO-control = 26.2%, rbST = 16.8%; JS-control = 19.9%, rbST = 13.3%; P < 0.01). Treatment tended to affect the incidence of ketosis (HO-control = 8.2%, rbST = 10.0%; JS-control = 8.4%, rbST = 13.1%; P = 0.09). Postpartum BCS was (P < 0.05) lower for rbST treated cows (HO-control = 3.08 ± 0.03, rbST = 2.99 ± 0.03; JS-control = 2.83 ± 0.03, rbST = 2.80 ± 0.03). Yield of energy corrected milk (ECM) in the first 3 weeks postpartum in the HO herd was greater for rbST cows (control = 33.0 ± 1.3, rbST = 36.3 ± 1.3kg/d; P = 0.05) but yield of ECM in the first month postpartum was not affected by treatment in the JS herd (control = 26.6 ± 0.6, rbST = 27.7 ± 0.6 kg/d; P = 0.15). Milk yield in the first month postpartum was (P = 0.05) increased by rbST treatment (HO-control = 35.0 ± 0.9, rbST = 37.9 ± 0.8kg/d; JS-control = 26.9 ± 0.8, rbST = 28.1 ± 0.8kg/d). Treatment of periparturient cows with small doses of rbST improved postpartum health and increased milk yield.