To the Editor: Pneumocystis carinii is a protozoan that causes pneumonia in more than 80 percent of patients with the acquired immunodeficiency syndrome (AIDS). The treatment of P. carinii pneumonia generally consists of systemic pentamidine or trimethoprim–sulfamethoxazole and, more recently, aerosolized pentamidine. P. carinii choroiditis has recently been described in four patients with AIDS, all of whom had been treated with aerosolized pentamidine. We have seen two patients with presumed P. carinii choroiditis, both of whom had been treated with inhaled pentamidine. We present the case history of one of these patients.A 28-year-old man was given a diagnosis of …