Before 1950 no reliable or safe therapy existed for systemic and invasive mycoses, and only traditional and empirical topical preparations were available for dermatomycoses. Two distinct eras of rapid progress in antifungal therapy followed: first, in the 1950's came the introduction of the polyenes, nystatin and pimaricin for cutaneous, vaginal and intestinal candidiasis, and amphotericin B for the treatment of severe systemic mycoses. The second phase saw the successful introduction and clinical use of 5-fluorocytosine and several imidazole derivatives some twenty years later, at a time when the vast increase in iatrogenic systemic mycoses caused by opportunistic fungi had created an urgent and pressing need for new agents in addition to those still effective.