The aim of this study was to evaluate the effect of yeast culture plus enzymatically hydrolyzed yeast on milk production and metabolic profile during transition period of dairy cows. Twenty-nine multiparous Holstein cows were blocked by milk production on the previous lactation and randomly assigned into 2 groups: one received 28 g/d top-dressed yeast culture plus enzymatically hydrolyzed yeast (YC-EHY; Celmanax, Arm & Hammer Animal Nutrition, Princeton, NJ), while the control group did not receive the supplement. The experiment was conducted from d −35 relative to calving until 150 of lactation. During this period cows were weighed weekly and their body condition score (BCS) evaluated. Cows were milked twice daily and were kept in a semi-extensive production system. Milk yield and milk composition were evaluated weekly from calving to 150 DIM. Plasma samples collected on −21, −14, −7, 0, 3, 7, 14, 21, 28, 35, and 42 d relative to calving were analyzed for β-hydroxybutyrate (BHBA), Nonesterified fatty acids (NEFA), cholesterol and plasma urea nitrogen (PUN). Data were analyzed using mixed models with repeated measures over time. The YC-EHY group had higher milk yield (27.75 vs. 24.98 ± 0.5 kg/d, P = 0.05) versus the control group. However, the control group had more milk protein concentration (2.97 vs. 2.87 ± 0.03%/d, P = 0.03) in comparison with YC-EHY group. Other milk compounds were not affected (P > 0.05) by supplementation. No differences (P > 0.05) were observed for BHBA, NEFA, cholesterol, and PUN concentrations during the transition period. Also body weight and BCS were not affected (P > 0.05) by supplementation. In conclusion, yeast culture plus enzymatically hydrolyzed yeast supplementation increased milk production during the first half of lactation, however, metabolic profile are not affected by supplementation during the transition period in dairy cows.