A 7-year-old male boxer is presented for evaluation of a prostatic mass. Physical and ultrasonographic examinations suggested a paraprostatic cyst. Surgery confirmed the presence of a large calcified cavitary mass in the paraprostatic region that was resected. An omentalization of both pedicle and prostatic cyst was performed. The animal recovered uneventfully. The origin of paraprostatic cyst is not clear, but the outcome is usually good after surgical excision.