This study was conducted to investigate the expression of oligopeptide transporter 2 (PepT2) and its potential function in bovine mammary gland. First, the PepT2 mRNA and protein were determined in cultured mammary epithelial cells. Then the effects of lactogenic hormones (prolactin, hydrocortisone or insulin) and substrate (threonyl-phenylalanyl-phenylalanine) on PepT2 were investigated. The PepT2 mRNA and protein were successfully detected in bovine mammary epithelial cells. PepT2 gene expression was enhanced by the addition of 50, 500 and 5000 ng/ml prolactin, 10 and 100 ng/ml hydrocortisone, and 50, 500, 5000 and 50 000 ng/ml insulin. PepT2 mRNA abundance was increased when 5, 10 and 15% of threonyl-phenylalanyl-phenylalanine was included. Responses of PepT2 to lactogenic hormones and oligopeptide inferred that it may play an important role in bovine mammary gland.