Background: Obesity induced pulmonary dysfunctions has been well documented but little is known about the relationship between obesity and blood gases. This study examined the association between obesity related anthropometric measurements and blood gases changes among military personnel. Methods: A total of 103 healthy military personnel were recruited, their anthropometric indices namely Body Mass Index (BMI), waist circumference (WC), hip circumference (HC), waist-hip-ratio (WHR) and percentage of body fat (PBF) were obtained. 1 ml of arterial blood was withdrawn from the radial artery for arterial blood gases analysis. Results: 75.2% (n=79) and 24.8% (n=26) of subjects with and without obesity, respectively. PaO2 was significantly inversely correlated with BMI, (r = -0.435, p = 0.000), WC (r = -0.345, p = 0.000), WHR (r = -0.227, p = 0.021) and PBF(r = -0.418, p = 0.000). The pCO2 was significantly correlated with BMI (r = -0.226, p=0.022), WC (r=0.256, p=0.000), HC (r=0.432, p=0.000), WHR (0.225, p=0.022) and PBF (0.319, p=0.001). The BMI, WC, WHR and PBF (except HR), were also significantly inversely correlated with low Pa HCO3- (r = -0.275, p = 0.005), (r = -0.291, p=0.003), (r = -0.3, p=0.002) and (r= -0.319, p=0.001) respectively. Conclusion: All the anthropometric measurements studied except HC were predictors for blood gases changes in individuals with obesity. Both overall and central obesity were associated with hypoxemia, hypercapnia and low bicarbonate suggesting that blood gases changes could be due to combination of obesity-induced physical mechanical respiratory changes, fat contents and obesity related biochemical.