A retrosepctive evaluation has been made of blood pressure, pulse rate, and number of anginal attacks per day in twenty-one patients diagnosed as Prinzmetal's Angina and treated with the investigational drug nifedipine. The effect of combining nifedipine with short- and long-acting nitrates or with propranolol was also evaluated. In consideration of the statisically significant reduction in the number of anginal attacks per day, p less than 0.001, together with the non-significant mean changes in blood pressure and pulse rate as well as the compatibility with the other drugs, it is concluded that nifedipine is a very useful drug, in a dose range of 30--120 mg per day, for the treatment of Prinzmetal's Angina. Recorded side-effects were of minimal severity and in no case caused nifedipine therapy to be discontinued.