The case notes of all patients less than 30 years who had a discharge diagnosis of rheumatic fever or rheumatic heart disease and were admitted to Rotorua Hospital between January 1972 and April 1983 were examined. Information was analysed by computer and a register was begun locally on a card index system which may be computerised in future. There were 237 admissions involving 188 individuals with an average stay of 37 days. At least 63% of the 188 individual patients are known to have rheumatic heart disease. The average annual incidence for rheumatic fever was 20.1/100 000 with a Maori incidence in the 5-19 age group of 153.0/100 000. The incidence was significantly higher in areas where males had a lower income. The recurrence rate for rheumatic fever during the study period was 12.4%. It is recommended that the register should be continued to gather epidemiological data and to conduct an effective secondary prophylaxis programme using long acting intramuscular penicillin.