In a series of 3172 consecutive autopsies of stillbirths, infants and children performed over a 12-year period from 1978 to 1989 at the Department of Pathology, Outram Road, Singapore, urinary tract malformations were found in 78 cases (2.5%). The urinary tract abnormalities were of 6 major groups: hydronephrosis and/or hydroureter (35.9%), cystic disorders (29.5%), renal agenesis (26.9%), horseshoe kidney (11.5%), renal hypoplasia (5.1%) and pelvic kidney (1.3%). Other series have reported incidences of urinary tract malformations ranging between 2.7% and 11%, depending on the source of the study material. Our local incidence appears to fall below the lower end of the scale, but may not reflect an accurate comparison because of the differences in the denominational base.