Cystic lesions deriving from the omentum are rare benign clinical conditions of uncertain etiopathogenesis. In this report we describe a case of antenatal diagnosed intra‐abdominal cystic mass, which, due to the absence of symptomatology and constant ultrasound morphology over time, did not require immediate treatment. The present patient was followed up until surgery, which was performed at 4 years of age: on laparoscopy a cyst within the greater omentum was identified and excised. Histopathology indicated a cyst with epidermoid structure, which is unusual among the omental cysts reported in the literature.