Candida is a fungus present in the mouths of up to 60% of healthy people, but overt infection is associated with immunosuppression, diabetes, broad-spectrum antibiotics, and corticosteroid use. In most people, untreated candidiasis persists for months or years unless associated risk factors are treated or eliminated. In neonates, spontaneous cure of oropharyngeal candidiasis usually occurs after 3 to 8 weeks.We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent and treat oropharyngeal candidiasis in: adults having treatment causing immunosuppression; infants and children; people with diabetes; people with dentures; and people with HIV infection? Which treatments reduce the risk of acquiring resistance to antifungal drugs? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 51 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review we present information relating to the effectiveness and safety of the following interventions: antifungals (absorbed or partially absorbed, and topical absorbed/partially absorbed/non-absorbed: e.g., amphotericin B, clotrimazole, fluconazole, itraconazole, ketoconazole, miconazole, nystatin, posaconazole) used for intermittent or continuous prophylaxis or treatment, and denture hygiene.