Mesenteric cysts are uncommon incidence benign abdominal mass and occur in patients of any age. Approximately one third of patients with these lesions are children. They may be asymptomatic but may present with pain abdomen or abdominal mass and sometimes with complications like acute abdomen.They commonly originate from any mesentry from duodenum to rectum.They may extend from the base of the mesentery into the retro-peritonium. A mesenteric cyst originating in the sigmoid mesocolon is a very rare finding. Here we present a case of mesenteric cyst located in the sigmoid mesocolon of a 5 yrs female child with abdominal pain and lower abdominal lump.