In this study, we analysed the prevalence of diabetes in Inner Mongolia and explored the relationship between dietary patterns and diabetes using the Chinese Dietary Balance Index-16 (DBI-16). This study was a surveillance survey of Chronic Disease and Nutrition Monitoring among Chinese Adults in Inner Mongolia in 2015. Dietary data were collected using the 24-h dietary recall and weighing method over three consecutive days. Dietary quality was evaluated via the DBI-16. A generalised linear model was used to examine the associations between the DBI-16 and dietary patterns. The relationship between dietary patterns and diabetes was analysed using logistic regression. In Inner Mongolia, the diabetes prevalence was 8·5 % and the estimated standardised prevalence was 6·0 %. Four major dietary patterns were identified: ‘meat/dairy products’, ‘traditional northern’, ‘high cereal/tuber’ and ‘high-salt/alcohol’. Generalised linear models showed that the ‘meat/dairy product’ pattern was relatively balanced (βLBS = –1·993, βHBS = –0·206, βDQD = –2·199; all P < 0·05) and was associated with a lower diabetes risk (OR 0·565; 95 % CI 0·338, 0·945; P < 0·05) after adjusting for potential confounders. The other three dietary patterns (i.e. ‘traditional northern’, ‘high cereal/tuber’ and ‘high-salt/alcohol’) exhibited relatively unbalanced dietary quality and were unassociated with diabetes risk. Diabetes prevalence in Inner Mongolia was moderate. The dietary quality of the ‘meat/dairy product’ pattern was relatively balanced and was correlated with a decreased risk of diabetes prevalence, suggesting that dietary quality may help decrease diabetes prevalence and provide a suggestion for local dietary guidelines.