The Cryptococcus has become a major cause of meningitis in patients infected with the human immunodeficiency virus (HIV), and the expression of cryptococcal infection in this population of patients is quite unique. Often the infection is devoid of inflammatory response and is associated with very high antigen and fungal titers. Response to amphotericin therapy is erratic, and relapse is common. We have asked Dr. William E. Dismukes, principal investigator of the NIAID Mycoses Study Group, to discuss the following clinical questions: When and how does cryptococcal infection in HIV-infected patients present? How does it differ in HIV-infected and non-HIV-infected individuals? How is the diagnosis established? What is the sensitivity of the CSF cryptococcal antigen test? Is the serum antigen test of any value? What is the best way to treat patients--the recommended drugs, dosages, and duration of therapy? Is maintenance therapy necessary, and finally, what drugs are available for it? [Please note that an AIDS training program is now available for members of the Infectious Diseases Society of America and that details of this program appear in the Notices section of this Journal issue (pages 859-60).]