The authors present a case of left epididymo-orchitis associated with rectal adenocarcinoma and suspected fistula between the left seminal vesicle and the rectum. This fistula was confirmed by pelvic computed tomography and surgical exploration. Treatment consisted of parenteral antibiotics and surgical drainage of the abscess associated with colorectal resection. This is an original case, as, retrospectively, the cancer of the rectum, diagnosed 4 days previously, was found to be responsible for the recto-seminal fistula and the seminal vesicle abscess.