Transcatheter venous embolization with metallic coils is a safe and reliable method for the treatment of pelvic congestion syndrome and pelvic varicocele. While rare, coil migration to the pulmonary arteries is potentially fatal. We report the migration to the pulmonary artery of a cluster of nine metallic microcoils placed in the internal iliac vein to obliterate giant rectal varices. Our patient suffered no severe sequelae. To avoid coil migration to the pulmonary arteries, the coils chosen for placement must take into consideration the characteristics of the target vessels, particularly of larger veins.