Experimental data have shown that low concentration of amphotericin B disrupts of the fungal cellular membranes, enhancing entrance of rifampicin into citoplasm, where it acts specifically as an antifungal agent against Histoplasma capsulatum, Blastomyces dermatitidis and Candida albicans. Amphotericin B in half dosage combined with rifampicin is more effective than when used alone in full dosage. The Authors discuss the possible indications of this association in the therapy of paracoccidioidomycosis, and report its efficacy in three cases of this disease only controlled after its use.