Report of a case of sirenomelia (mermaid) anomaly. This male fetus was born from a 30 year-old mother and remained alive for 18 hours. The following anomalies were present: Potter's syndrome, absence of external genitalia and internal genital ducts, presence of two male gonads, renal agenesis, lack of bladder and ureteral ducts, single umbilical artery. Were also found: right radial dysplasia, Fallot tetralogy, T.E. fistula with esophageal atresia, lumbo-sacral spina bifida cystica.