Abstract: ObjectiveTo determine the prevalence of overweight and obesity in adult populations in Mianyang, Sichuan province. MethodsA questionnaire survey involving physical examinations were conducted in 262 434 adults (≥18 yr.) selected through multi-stage random sampling from November 2014 to September 2015 in Mianyang city. ResultsAmong the people surveyed, 79 981 (30.48%) were overweight, and 23 010 (8.77%) had obesity. The male participants had a higher percentage (32.28%) of overweight than females (29.10%, P<0.01), but lower obesity rate (8.53%) than females (8.95%, P<0.01). Those aged 50-59 yr. had the highest prevalence of overweight (39.26%) and obesity (12.07%). The participants with up to junior middle school education were most likely to be overweight (35.02%) and obese (10.57%). Overweight and obesity were most prevalent in the unemployed: 36.87% and 12.65%, respectively. Fucheng had higher prevalence of overweight (30.01%) and obesity (10.14%) than Jiangyou (29.97% and 7.46% respectively, all P<0.01). The prevalence of overweight and obesity was higher in the smokers (32.88% and 9.46%) than in the non-smokers (30.02% and 8.64%, all P<0.01). Those who drank alcohols had higher prevalence of overweight and obesity (33.43% and 9.72%) than those who did not drink alcohols (29.78% and 8.54% respectively, all P<0.01). ConclusionHigh prevalence of overweight and obesity in adult populations in Mianyang is evident, especially in those who are 50-59 years old, unemployed, drinking alcohols, smoking, and have low educational level.