This study determined the prevalence and risk factors for flat foot among 18–21-year-old male Saudi Arabian army recruits. Among 2100 military recruits, the prevalence of flat foot was 5.0%. A case–control logistic regression analysis of risk factors (104 cases and 412 controls) showed family history, wearing shoes during childhood, obesity and urban residence were significantly associated with flat foot. No associated complaints were reported among the cases and thus flexible flat foot does not seem to be a cause of any disability.