Background: Pityriasis versicolor (PV) is a mild but recurrent superficial fungal infection of stratum corneum. Many predisposing factors such as late teen and young adulthood age, tropical and subtropical climate (and to a lesser extent temperate climate), immunosuppression, malnutrition, use of oral contraceptives, hyperhidrosis, poor hygiene and a few other factors have been proposed for this condition. Aim: Regarding these probable and possible risk factors, we felt that jail is a unique population which can be affected by this infection and therefore we decided to evaluate some aspects of this infection in this population. Methods: In this cross-sectional study in male prisoners of Bandarabbas city, 230 prisoners were randomly selec...