High body mass index, increased weight-bearing activity, ligament laxity are risk factors for pes planus, however, there is no research that looks for the relationship between these three risk factors in athletes. Adult athletes have a higher prevalence of pes planus than young athletes. In a conceptual framework regarding the etiology of injury in athletes, the interaction of multiple injury risk factors will further increase the risk of injury to athletes. This study aims to determine the relationship between body mass index, type of weight bearing activity and the Beighton and Horan Joint Mobility Index with pes planus in adult athletes. Secondary data from athletes screening of Regional Exercise Center (PUSLATDA) East Java was used in this study. Randomization technique was applied to recruit 96 proper respondents. Binary Logistics Regression test for calculating the relationship between BMI, type of weight bearing activity (high/low impact sport), BHJMI score and Chippaux-Smirax Index (CSI) with the statistical significance of p?