Objectives: This study aimed to investigate and compare the prevalence of oral mucosal lesions in a group of psoriatic patients and healthy subjects, and its correlation to multiple clinical parameters. Study design: 100 psoriatic patients and 100 closely matched controls underwent clinical oral examination. Oral lesions were diagnosed according to the criteria proposed by the World Health Organization (WHO). The patients filled the Hospital Anxiety and Depression (HAD) questionnaire and the Dermatology Life Quality Index (DLQI). The severity of psoriasis was assessed by the Psoriasis Area and Severity Index (PASI). Categorical variables were evaluated using Chi-square test or Fisher's exact test with overall significance set at p< 0.05. Results: Oral mucosal lesions were diagnosed in 43 (43%) psoriatic patients and 17 (17%) control subjects (p=0.000). Comparing psoriatic patients to control subjects the prevalence of fissured tongue (FT) was 35% vs. 13% (p=0.000); geographic tongue (GT) 17% vs. 9% (p=0.09); combination of FT and GT 5% vs. 5% (p=1.00); oral candidosis 3% vs. 0% (p=0.81); leukoedema 1% vs. 3% (p=0.62); physiologic melanin pigmentations 4% vs. 1% (p=0.37) respectively. The clinical type of psoriasis, duration of the disease, method of disease management (medicated vs. non-medicated for psoriasis), smoking habit, psychological status or the disease severity did not influence the prevalence of FT and GT. Psoriatic patients who experienced 'very large' to 'extremely large' adverse effect of psoriasis on their quality of life have significantly higher prevalence of GT (p=0.04). Conclusions: FT is significantly more common in psoriatic patients compared to controls; hence studies investigating the nature of this relationship are warranted. Oral health care providers should be aware of the predisposition of psoriatic patients to oral candidosis.