A retrospective analysis was made of cases of Chronic Pulmonary Histoplasmosis during the admission in which patients received amphotericin B to determine if there were features related to recurrence of the disease. There was significance at the p≤0.05 level in that the nonrecurrent cases tended to have a lower initial complement fixation titers using mycelial antigen; had initial complement fixation tests which were likely to result in no reaction using either mycelial or yeast antigen; and had more rapid drops in the complement fixation values using the yeast antigen. Although the present evaluation does not suggest an absolute minimum effective dose of amphotericin B, it would seem plausible to administer a course of at least 2300 mg if the initial complement fixation test was nonreactive but if the drug was tolerated well by the patient and the initial complement fixation test was reactive, the goal should be at least 2500 mg.