A patient with symptomatic urticaria pigmentosa who responded to nifedipine therapy is reported. Relief from cold-induced urtication and flushing was obtained with 10 mg taken orally three times daily. Calcium influx is an early step in the degranulation of mast cells. We hypothesize that the beneficial effect of nifedipine was due to calcium-channel blockade causing elevation of the mast cell threshold for degranulation.