Omental cyst is rare congenital anamoly of gastrointestinal tract. It is represented as abdominal distension. Occasionally, it may be presented with acute abdomen due to twisting of omental cyst and omentum and other complications. The ultrasonography and CECT abdomen are useful to make diagnosis of abdominal cyst. Complete surgical excision of cyst is definitive treatment. We are presenting a case of giant omental cyst in a pediatric female patient aged 3 year and 6months.