Candida spp. is the most frequent fungi which causes opportunistic infections in humans. In ‘immunocompromised’ hosts, severe systemic candidiasis may occurred. Candida spp. grows optimally at 37°C and a relatively neutral pH, the condition which is similar to that of the human body. Candida spp.is a dimorphic fungus and has the ability to adhere to certain surfaces and to form biofilms. Candida spp. produced ‘secretes aspartyl proteinase’ (Sap) which assist this organism in colonization and infecting the host. Candida spp. also secreted phospholipase, lipase, hyaluronidase, chondroitin sulfatase and enolase, which are responsible as its virulence factors. Through its metabolism, Candida spp. produces neurotoxins such as formaldehyde, acetaldehyde, arabinitol and arabitol. High concentration of ethanol, one of Candida’s metabolite, may cause alcohol intoxication in the host. Functional characteristics and metabolites of Candida spp. apparently play an important role in the pathogenesis of candidiasis. The presence of Candida spp. is not always harmful to humans. Candida spp. is a normal flora in human body. This organism also produces useful metabolites for food industry, such as xylitol, erythritol, mannitol and ethanol.