Splenic cysts are rarely found or diagnosed. Excluding cases of trauma, the events preceding their development have not been fully understood. We describe a 22-year-old woman in her 34th week of pregnancy in whom ultrasound revealed a cystic lesion 8 x 10 cm. in diameter in the left upper abdomen. Further imaging tests followed by laparotomy confirmed the splenic origin of the cyst. Splenectomy was performed and the lesion was histopathologically defined as an epidermoid cyst.