Although garlic has been used in Chinese traditional medicine for its medical properties for thousands of years, investigations into its mode of action are relatively recent. The purpose of this study was to evaluate the in vitro anti-fungal efficacy of the active principle of garlic, pure allicin and polybutylcyanoacrylate (PBCA) nanoparticles (NPs) loaded with allicin. Pure allicin was prepared by reacting synthetic alliin with a stabilized process of the garlic enzyme alliinase. PBCA NPs were prepared by emulsion polymerization method and pure allicin was wrapped into it. The in vitro efficacy of pure allicin and PBCA-allicin NPs to Candida albicans, Cryputococcus neoformans, Trichophyton rubum, Microsporum gypseum, M. canis and Epidermophyton floccosum was examined and evaluated by MIC and MFC. The MIC of PBCA-allicin NPs to C. albicans (2.93 x 10(-2)mg/ml), T. rubum (1.46 x 10(-2)mg/ml) and E. floccosum (1.46 x 10(-2)mg/ml) was significantly lower than that of pure allicin (5.86 x 10(-2)mg/ml, 2.93 x 10(-2)mg/ml, 2.93 x 10(-2)mg/ml, respectively); accordingly, the MFC of PBCA-allicin NPs to C. albicans (5.86 x 10(-2)mg/ml), T. rubum (2.93 x 10(-2)mg/ml), E. floccosum (2.93 x 10(-2)mg/ml) and M. canis (2.93 x 10(-2)mg/ml) also decreased dramatically. These favourable results indicated that pure allicin has stronger in vitro anti-fungal efficacy to six tested fungi than alliinase and alliin. Moreover, it has improved significantly after pure allicin being wrapped into PBCA NP, which may be due to the NP's good prolonged release effect and nano-scale dimensions.