When this report was started, to my knowledge only one reference to agranulocytosis from tripelennamine (pyribenzamine®) hydrochloride had appeared in the literature.1 At the time this report was completed, Cahan, Meilman and Jacobson2 had currently reported a case of agranulocytosis following tripelennamine therapy. The following case is one of agranulocytosis after the drug had been taken three times daily for eight weeks because of urticaria. No other medicaments were involved. REPORT OF A CASE A nurse aged 39 sought medical attention because of malaise, prostration and urticaria, the last mentioned of eight weeks' duration. The distribution of the urticaria was general, including her eyelids and lips. The patient started taking tripelennamine hydrochloride, 50 mg. three times daily, when the lesions first appeared. The medicament seemed to keep the urticaria fairly well controlled. However, after seven weeks she began to feel weak, and this weakness progressed to almost complete