OBJECTIVE Acute rheumatic fever (ARF) is a major cause of morbidity and mortality in developing nations. The objective of this study was to determine the disease burden of ARF among the indigenous and non-indigenous populations of the Northern Mariana Islands. METHODS This was a chart review of all pediatric outpatients seen from 1984 to 2006 with ICD-9 codes corresponding to rheumatic fever or any rheumatic cardiac sequelae. The study was set in the only comprehensive inpatient facility and only public pediatric clinic in the Northern Mariana Islands. RESULTS One hundred fifty-eight cases of ARF were identified. Age at diagnosis ranged from 2.9 to 17.1 years (median 10.6 years). Fever and carditis were the most common presenting findings. The average annualized incidence of ARF was 85.8 per 100,000 person-years for those aged 5-14 years. Sixty-six percent of patients with ARF were of Chamorro or Carolinian ancestry, despite comprising only 39% of the total population, with a combined average annualized incidence of ARF of 167 per 100,000 person-years. CONCLUSIONS This is the first documentation of the incidence of pediatric ARF in the Northern Mariana Islands, delineating the large disease burden in the indigenous and other Pacific Island ethnic groups. Impediments to diagnosis and primary and secondary prevention were identified. The data provide strong support for the need for primary and secondary prevention of ARF.