The clinical outcome after the initial year of therapy with either diltiazem (D), nifedipine (N), or verapamil (V) was examined in 45 patients with rest angina. Age, frequency of angina, duration of symptoms, and ejection fraction were similar in all three treatment groups. Coronary artery disease was present in 60% of patients (5 of 13 given D, 8 of 16 given N, and 14 of 16 given V). Coronary spasm was suspected (ST elevation with angina) or documented (angiographically) in 35 (78%) patients. Twenty-nine (64%) patients had greater than 50% decrease in angina without a coronary event (9 taking D, 11 taking N, and 9 taking V). Coronary events (sudden death, infarction, and hospitalization for unacceptable angina control or bypass surgery) occurred in 13 (29%) patients (two taking D, four taking N, and seven taking V). To achieve these responses, 20 (44%) patients required additional antianginal drugs (long-acting nitrates, beta blockers, or other calcium blockers). Four of these 20 patients were taking D, nine were taking N, and seven were taking V. Seventeen (38%) patients experienced a side effect (none taking D, 6 taking N, and 11 taking V). Although rest angina can be controlled in the majority of patients during the initial year of treatment with calcium blockers, additional therapy is often required. Furthermore, the clinical course of patients presenting with rest angina remains unpredictable, even during calcium blocker treatment. Morbid events continue to occur, related in part to the extent of coronary artery disease.