Fetus in fetu was first identified in the early 19th century by Meckel. It is a rare congenital anomaly which occurs from anomalous embryogenesis in which a malformed parasitic twin is found within the body of the normally developed host. In most cases, the parasitic twin is anencephalic and usually contains a vertebral column and budding limbs. The upper limbs are less developed than lower limbs, and are usually located in the abdomen of the autosite. Diagnosis is often made preoperatively with ultrasonography, plain radiography, computed tomography, or magnetic resonance imaging. Histopathological findings confirm the diagnosis and the recommended treatment is complete surgical excision of mass. We report a case of 15-month-old baby boy of Nepalese origin referred to our hospital with mass in abdomen diagnosed during neonatal period.