Two cases of dipyrone-induced agranulocytosis are described. In the first one, the disease was due to a single administration, in the second one, to prolonged therapy. The possible pathogenic mechanism is discussed, which can be immunologic and/or toxic. The effectiveness of some of the drugs and general supportive measures applied is discussed. Health education of the patient, in conjunction with careful attention by the physician, may play an important role in the prevention of this pathological condition.