A parasitic body, i. e. the fist-sized trunk with the arms and legs was attached to the epigastric region of a male newborn at full-term birth. The parasite showed spontaneous urination and movement of the extremities, and was detached successfully. The autosite died of cyanosis and dyspnea 7 days after birth. The autosite weighed 2,800g. No external anomalies except for the parasitic body were present. Cardiac anomalies including ventricular septal defect, overriding of the aorta and patency of the foramen ovale were detected. Besides, acute bronchopneumonia and congestion of the liver, kidney and spleen occurred. An artery arising from the right subclavian artery entered into the parasite in the region of the xiphoid process after running down behind the sternum. The blood circulating through the parasite flowed back into the left atrium of the autosite. The parasite weighed 400g. The upper and lower extremities were almost well-developed on both sides. No anomalies of the hands and feet were found. The head, thorax, upper abdomen and vertebral column were defective. In the abdominal cavity there were blind-end isolated small and large intestines with the appendix. No rectum and anus were formed. The uro-genital organs consisting of one fused kidney with the adrenal glands, urinary bladder, two ureters, prostate, penis and two testicles in the scrotum were also found. No anomalous genitals were seen. On x-ray examination, the autosite revealed almost complete formation of the skeleton. In the parasite the bones of the upper and lower extremities and pelvis were clearly shown, but the cranium, vertebrae, sternum and ribs were not indicated. It was pointed out that in the autosite cardiac anomalies were found, and that in the parasite the uro-genital organs as well as the lower portion of the skeleton were relatively well-developed.