Congenital cystic lesions arising in the omentum are a rare finding in the paediatric age group. They are difficult to diagnose preoperatively as they have few distinct features; the diagnosis is often confirmed only at lalaparotomy. They are thought to arise due to a developmental abnormality of the lymphatic system. Two cases are presented and the literature reviewed. The treatment of choice is complete resection. Long-term follow-up is unnecessary due to their benign nature.