Spiramycin, a macrolide antibiotic, has been advocated for the treatment of cryptosporidiosis. The disease most commonly occurs in patients with AIDS and can be debilitating, as diarrhea and malnutrition may be contributing factors in the death of these patients. Until recently, treatment for cryptosporidiosis has been largely symptomatic. Response rates with drug therapy such as metronidazole, quinidine-clindamycin, and pentamidine have been extremely poor. Although response to spiramycin has appeared promising, there have been several reported cases of treatment failure. Further investigation with the agent is advocated to determine its role in the treatment of cryptosporidiosis.