AbstractA case‐control study of birth defects was carried out in Kandang Kerbau Hospital in Singapore for a three‐year period from January 1986 until December 1988. This paper presents the descriptive profile of birth defects among livebirths seen in that hospital. Out of 44,842 livebirths, 678 babies were found to have birth defects, giving a prevalence of 15.13 per 1000 livebirths (95% CI 14.0–16.2). The musculoskeletal system was the most frequently affected system accounting for 161 cases with a prevalence of 3.59 per 1,000 livebirths (95% CI 3.06–4.19), followed by 111 cases with defects of the gastrointestinal system (2.47 per 1,000 livebirths 95% CI 2.04–2.98), 88 cases of chromosomal disorders (prevalence of 1.96 per 1,000 livebirths 95% CI 1.57–2.42), 78 cases with defects of the cardiovascular system (1.74 per 1,000 live‐births 95% CI 1.38–2.17), 73 cases with defects of the urogenital system (1.63 per 1,000 livebirths 95% CI 1.28–2.05), and 52 cases with defects of the central nervous system (1.16 per 1,000 livebirths 95% CI 0.87‐1.52). The prevalence of cleft lip, cleft palate in isolation, and cleft lip and palate combined was 1.72 per 1,000 livebirths and the occurrence of Down's syndrome was 1 in 700 livebirths. When reviewed 6 weeks postpartum, the rate of false positives at birth was 4%. In a control group of 709 “normal” cases at birth, the rate of cases not detected at birth but detected at 6 week follow‐up, false negatives was 0.84