The objective of this study was to determine the prevalence, awareness, treatment, and control of hypertension, diabetes, and high total cholesterol (TC) by BMI categories. Data from the National Health Examination Survey III of Thai adults aged≥18 years were used. Age and sex-adjusted prevalence and awareness of the 3 risk factors increased with increases in BMI categories. Proportions of awareness of hypertension, diabetes, and high TC were 27.9%, 33.4%, and 13.6%, respectively, in the BMI≥30 kg/m2 group. The highest treatment rates of 19.0% for hypertension and 10.1% for high TC were found in the BMI≥30 kg/m2 group and the highest treatment rate of 33.6% for diabetes in the 25 to 30 kg/m2 BMI group. There were no significant differences in the control rates of these risk factors across BMI groups. Improvement in detection, treatment, and control of these metabolic risk factors in all BMI subgroups is critical.