One hundred fifteen attacks of acute rheumatic fever were observed during the past two decades (1969 to 1988) at the Columbia-Presbyterian Medical Center; 104 were initial attacks and 11 were recurrences. The maximum number of cases (18) occurred during the first year of this period, 1969; thereafter the annual incidence decreased until a resurgence was apparent in 1985 to 1986, with 25 cases. There were no differences in the frequency of major manifestations nor the severity of carditis in the 1970s compared with the 1980s. Polyarthritis alone was present in 51 cases, carditis alone in 31, and combined carditis and polyarthritis in 28; chorea was diagnosed in 5. Congestive heart failure occurred in 17 attacks of carditis, including one death from fulminant disease in 1982. In contrast to recent reports, the majority of the affected population was urban, low income, and from crowded communities: more than half were Hispanic, predominantly from Dominican Republic families. The prevalence of acute rheumatic fever underscores the need for early detection and treatment of streptococcal pharyngitis. The observation that 9.5% of the attacks were recurrent reflects failure to comply with antimicrobial prophylaxis and reaffirms the need for more effective secondary prevention programs.