Display omitted •Consumption of cooked mung bean prevents obesity in mice fed with a high-fat-diet.•Consumption of cooked mung bean ameliorates lipid metabolic disorders.•Consumption of cooked mung bean reduces the hepatic steatosis and adipocyte size.•The partial mechanism of mung bean’s beneficial effects involves gut microbiota. Mung bean is shown having several health benefits, but a little bit of knowledge is known about its effects on high-fat diet (HFD)-induced obesity or its relationship with gut microbiota composition changes. Here, it was observed that consumption of HFD supplemented with cooked mung bean (30%, w/w) for 12 weeks effectively alleviated body weight gain and lipid metabolic disorders, which was accompanied by a decrease in hepatic steatosis and adipocyte size. Furthermore, high-throughput sequencing of 16S rRNA revealed that mung bean supplementation prevented the HFD-induced gut microbiota dysbiosis, which was likely associated with the decreased relative abundance of several HFD-dependent taxa (Ruminiclostridium_9, Mucispirillum, Bilophila, Blautia, Ruminiclostridium, and Odoribacter), and the increased relative abundance of norank_f__Muribaculaceae. Spearman’s correlation analysis indicated that those genera were closely correlated with obesity-related indices. Collectively, the prevention of obesity by mung bean supplementation was at least partially mediated by structural modulation of gut microbiota.