Fetus in fetu (FIF) is an extremely rare pathology in which a malformed fetus is located in the body of its twin. It may occur as a result of an aberration of the twinning process. It is important to distinguish this condition from a teratoma. This article emphasizes the importance of the various modalities in the antenatal diagnosis and post-natal follow-up of FIF. An appropriate early intervention if instituted results in a good prognosis. Only few cases of FIF have been reported in medical literature. We present a case which was antenatally diagnosed and proven on histopathology post-natally. This case report illustrates the importance of multimodality imaging techniques in the diagnosis of this condition.