The study of experimental fungal infections requires effective animal models. Two such models in the rabbit model have been developed and applied to various aspects of topical antifungal therapy. In these models, the polyenes, as a class, are superior in efficacy to the imidazoles and flucytosine, but efficacy is clearly strain-related. Corticosteroids, when administered concomitantly with antifungal agents, adversely influence antifungal activityin vivo. This steroid effect is inversely proportional to the efficacy of the antifungal agent. The corneal epithelium appears to be a significant barrier to the penetration of the polyene antibiotics. Although the predictive power ofin vitrosusceptibility testing as a guide toin vivoefficacy is uncertain, a correlation was seen between thein vivoand in vitro effect for amphotericin B against three strains ofCandida albicans.