Recombinant bovine somatotropin (rbST) could be an important tool to improve immune status and to optimize health in transition dairy cows. Therefore, the objective of this study was to investigate the effects of rbST on productive and metabolic parameters of periparturient dairy cows. The trial was conducted in 2 commercial herds in Paraná and São Paulo States, Southern Brazil, from September 2016 to August 2017. A total of 692 heifers and cows were blocked by lactation order and body condition score 28 d before calving. The Treatment group 1 was supplemented weekly with 0.6 mL (125 mg) of bovine somatotropin (Boostin^®, Merck) only in the prepartum period, the Treatment group 2 was supplemented weekly with 0.6 mL (125 mg) of rbST both in the prepartum and postpartum periods until the 21th day after calving, while the Control group received 0.6 mL of saline until the 21th day after calving. Three blood samples were collected on d 0, 6, and 13 postpartum. Data were analyzed using the MIXED procedure of SAS with a model containing the effects of farm, calving order, time, treatment, and treatment*time interaction as fixed effects and cow within treatment as a random effect. Average milk yield in the first 100 d of lactation did not differ (40.66 kg/d in the Control, 40.66 kg/d in rbST prepartum, and 39.98 kg/d in rbST pre- and postpartum; SEM = 1.6 kg/d, P = 0.61) among experimental groups. Analysis of metabolites on serum blood in the day of calving (NEFA, Ca, albumin, cholesterol, triglycerides, GGT and AST) did not demonstrate (P > 0.10) any beneficial effects of rbST supplementation, however the analysis of β-hydroxybutyrate (BHB) on serum blood in the 6th and 13th day after calving showed an increase (P < 0.05) in fat mobilization in the groups with rbST administration. These results suggest an increase in the incidence of clinical and subclinical ketosis, especially in the Treatment group 2 (rbST supplementation pre- and postpartum). In summary, rbST supplementation in the prepartum and immediate postpartum periods did not show positive results in this trial.