Oral candidosis is a mixed yeast-bacterial biofilm infection. Candida albicans is the most common causative agent although other Candida species are seen in medically compromised patients with a history of liberal azole usage. C. albicans is usually susceptible to all commonly used antifungals when tested in vitro. However, candida biofilms are highly resistant to most antifungals. Therefore, treatment of oral candidosis requires mechanical breakage of the biofilm in combination with topical polyenes. Azoles should be avoided in cases of recurrent infections due to risk of selection of resistant strains. Occasionally oral thrush is a symptom of an undiagnosed systemic disease.