Introduction: Obesity or high adiposity is known to be associated with various medical consequences, such as diabetes mellitus, hypertension, coronary heart disease and metabolic syndrome. High adiposity and poor cardiorespiratory fitness (CRF) have been found to be related with higher risks of developing cardiovascular disease (CVD). However, previous studies in Asia reported inconsistent findings on the association between obesity or high adiposity, based on various indicators, with impaired CRF. This study investigated the association between adiposity indicators and CRF in terms of maximal oxygen uptake (VO2 max) in adolescents from rural northeastern Thailand. Methods: This study was performed among 486 adolescents aged 14-15 years old in Khon Kaen province, Thailand. Adiposity indicators included body mass index-for-age z-scores (BAZ), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and percent body fat (%BF) based on deuterium dilution technique. Results: Male adolescents had higher WHR and VO2 max than female adolescents, while female adolescents had higher %BF and WHtR. Adolescents who had higher adiposity tended to have lower VO2 max, especially among females in which the lowest VO2 max was found in the highest quintile of adiposity indicators, including BAZ, WC, WHtR and %BF. Conclusion: Adolescents with higher adiposity tended to have poorer CRF. Based on previous knowledge that both high adiposity and poor CRF may lead to higher risks of developing CVD, this suggests that obese adolescents should be considered and managed at an early age in order to maintain optimal CRF.