Abstract: In the recent years, there has been a growing concern about the effects of marine natural products on human pathogens. It is determined that sacoglossan mollusks have special natural products which attracted more attempts and attentions. For the first time, in the present study antifungal activity of Plakobranchus ocellatus collected from the southern waters of Qeshm Island, the Persian Gulf has been investigated. Acetonitrile, ethanol and sodium phosphate buffer as organic and aqueous extracts were prepared from the whole body tissue and tested through seven concentrations against Candida albicans, C. parapsilosis and C. glabrata. The extractions with more responses against fungal strains were identified. Maximum and minimum inhibition zones were estimated for acetonitrile and sodium phosphate buffer extracts against C. parapsilosis and C. albicans, respectively. The organic extracts were the best solvents for extracting antifungal compounds. Acetonitrile extractions showed the best antifungal activity and C. glabrata was the most resistant strain against all P. ocellatus antifungal extractions.