Data in the literature regarding the prevalence of Candida in psoriatic and atopic dermatitis patients are controversial. We conducted a prospective study to determine the prevalence of Candida on the tongue, axillae and groin of psoriatic patients when compared with atopic dermatitis patients and normal controls. During the period 2003-2005, data were collected from 100 psoriatic patients, 100 patients with atopic dermatitis and 100 normal controls. Fungal test specimens for Candida were collected from the axillae, groin and tongue of each patient. There was no increase in the prevalence of Candida in intertriginous area of either psoriatic or atopic dermatitis patients. However, the prevalence of Candida on the tongue was significantly higher in psoriatic patients (32%) compared with atopic dermatitis (18%) (P = 0.024) and higher, although not significantly, than in normal controls (21%) (P = 0.08). Our study did not reveal higher prevalence of Candida in the axillae and groin of either psoriatic or atopic dermatitis patients. There was a higher prevalence of Candida on the tongue of psoriatic patients. The Candida of the tongue was asymptomatic and did not correlate with age, gender, type of psoriasis or severity of the disease, therefore we conclude that this is clinically irrelevant.