Hydatid disease of the urogenital system, especially seminal vesicles and prostate, or retroperitoneum is a very rare condition. Secondary dissemination of seminal vesicles has not been described before. We describe the transrectal ultrasonography (TRUS), CT and MRI findings of a secondary solitary hydatid cyst of the left seminal vesicle, in a patient with disseminated hydatid disease involving all abdominal organs except for right kidney. We obtained typical findings of hydatid cyst at all modalities.