The incidence of acute myocardial infarction (AMI) among urban blacks appears to be considerably less than that among whites. To evaluate this, all AMIs among Newark, NJ, residents in 1973 were evaluated, using the 1970 census for calculating age, race, and sex-specific rates. Death certificates of patients dead on arrival (DOA) from coronary heart disease (total 517) were also evaluated. Two hundred seventy-three AMIs were documented. Although crude rates per 100,000 population were higher for whites than for blacks, age-specific rates by decades from 20 to 80 revealed no differences. Coronary DOA rates were consistently higher among blacks than among whites, reaching approximately a 21 ratio in the older decades. The apparent rarity of AMI among Newark blacks is attributable to their relative youth compared to whites (77% under 40 vs 56%) and a higher out-of-hospital coronary death rate.