Flucytosine is a systemic antifungal drug that is readily absorbed from the gastrointestinal tract. The most clearly documented therapeutic effect has been in cryptococcosis, candidiasis, and chromomycosis. An important limitation of the use of flucytosine in all three diseases has been drug resistance arising during therapy. The addition of low-dose, intravenous amphotericin B to flucytosine therapy of cryptococcosis has appeared to decrease the frequency of secondary flucytosine resistance. In addition, the two drugs have an additive or slightly synergistic effect against flucytosine susceptible isolates of Cryptococcus and Candida. The combination is probably the treatment of choice in cryptococcal meningitis and offers promise in the therapy of systemic candidiasis and nonmeningeal cryptococcosis.