We report a case of bilateral persistence of the common mesonephric duct in a child. This anomaly is an error of implantation of the vas deferens in the distal part of the Wolffian duct. This abnormality is extremely rare (6 cases have been reported in the world literature). The diagnosis is usually incidental during laparotomy or on retrograde cystography (vesico-ureteric and vesico-deferential reflux). It is simple to treat: bilateral deferential ligation in view of the context of multiple malformations, in order to prevent ascending genital infections (prostatitis, epididymitis, testicular abscess). Only one case has been reported in adults, presenting in the form of a septic complication. This diagnosis must be considered in a context of atypical urogenital infection in a subject with other congenital abnormalities.