A retrospective analysis of the incidence of acute rheumatic fever (ARF) was undertaken in Memphis-Shelby County [Tennessee, USA] during the 5 yr period from 1977-1981. Cases were identified by review of local hospital records and by mail and telephone communication with 327 primary care physicians and neurologists. Patients (41) met the modified Jones criteria, of whom 16 had conditions that were diagnosed in Memphis but who resided elsewhere. The overall ARF incidence among Memphis-Shelby County residents was 0.64 cases/100,000 population each year. The highest rate, 3.74, was found among blacks age 5-17 yr residing in the inner city, while white children in the suburban and rural areas had a rate of only 0.49. Current strategies for prevention and diagnosis of ARF must take into account the extraordinarily low level to which the incidence of the disease has fallen in certain subburban USA populations.