Thirty-one patients with recurrent pericarditis were observed for periods of 2 to 19 years. Twenty-four had idiopathic pericarditis; four had postoperative or posttraumatic pericarditis, two had postinfarction pericarditis and one had recurrent pericarditis after anticoagulant-induced intrapericardial bleeding. In 24 patients (Group I), recurrences were documented by electrocardiographic changes, echocardiographic evidence of pericardial fluid or a pericardial rub as well as chest pain. In seven patients (Group II), recurrences were documented only by increased white blood cell count, increased erythrocyte sedimentation rate or fever in addition to pain. In 19 patients, the duration of the active or recurrent process was 5 years or more; in 7, it was 8 years or more. Three patients had cardiac tamponade in the initial attack; none had tamponade during recurrences. No patient developed congestive heart failure, constrictive pericarditis or cardiac arrhythmias with recurrences. Immunoelectrophoresis showed normal findings or minor deviations in 11 patients studied; B cell and T cell lymphocyte counts were normal in 10 patients and showed minor deviations in 3. Antinuclear antibody studies were normal in 19 of 22 patients and positive in low titer in 2. Most patients required adrenal steroid therapy for pain relief; steroid withdrawal was often difficult. Pericardiectomy was done in nine patients; in only two was this followed by clear-cut relief. In this group of 31 patients, 22 of whom were observed for 5 years or more, recurrent attacks of chest pain were the only major disabling feature of their pericarditis.