Ninety-six patients with polymyalgia rheumatica were identified in Olmsted County, Minnesota, during the 10-year period 1970 to 1979. Giant cell arteritis was found in 15 of the 96 patients. The average annual incidence of polymyalgia rheumatica in the population increased from 19.8 per 100 000 in persons 50 to 59 years of age, to a maximum of 112.2 per 100 000 in persons 70 to 79 years of age. Eighty-three of the 96 patients (86%) had recovered by the end of the study. Median duration of the disease was 11 months (range, 2 to 54 months). Polymyalgia rheumatica had no effect on survival. Both corticosteroids and nonsteroidal anti-inflammatory drugs were used in treatment. Response was more rapid in patients given corticosteroids, but nonsteroidal drugs were used successfully, especially in milder cases. Relapses and adverse reactions to treatment were more frequent in patients given corticosteroids. The findings show that polymyalgia rheumatica is a relatively common disease in middle-aged and older persons and generally runs a self-limited course.