Cot death is very rare in Hong Kong; this may be an important contributory factor to the low postneonatal mortality (3.1 per 1000). Over the 5 years 1980-84 only 15 cases of cot death were documented by forensic pathologists--an approximate incidence of 0.036 per 1000 live births. If the incidence was similar to that in western countries (2-3 per 1000), 800-1200 cot deaths might have been expected over this period. It is argued that this rare occurrence is real and not cot death masquerading as other causes of death. It is speculated that perhaps life-style (including crowded living conditions), the practice of placing babies supine in their cots rather than prone, and a lower frequency of preterm birth could contribute.