This study aimed to relate the serum levels of energy indicators (glucose and beta-hydroxybutyrate) and calcium to the occurrence of uterine and mammary diseases in the transition period of Holstein cows. One hundred and fifteen Holstein cows from a commercial herd were monitored starting one week before calving and during the first 2 weeks after calving. The presence of subclinical mastitis was monitored for 3 weeks postpartum using the California Mastitis Test (CMT) and somatic cell counting. Positive samples of subclinical mastitis were analyzed for bacterial identification. Clinical mastitis was monitored for 6 weeks postpartum, using data that were recorded by the farmer based on some established definitions. The presence of uterine disorders was identified for 3 weeks postpartum by clinical examination. Blood collections were made from all cows for determining calcium, glucose, and β-hydroxy-butyrate (BHB) the week before calving and twice during the postpartum (days 5 and 15 postpartum). A group of 70 healthy cows was used as control. Clinical mastitis was identified in 20% of the cows, subclinical mastitis in 10.4% and clinical metritis in 8.7% of the cows. The bacterial agents with the highest occurrence in subclinical mastitis cases were coagulase-negative Staphylococcus and Streptococcus. No relationships were observed between any of the biochemical metabolite studied and the uterine and mammary diseases in the cows during the studied period