Lifestyle changes in urban communities that are associated with the risk of diabetes include poor diet, lack of physical activity, and smoking that affect glucose metabolism so that blood glucose levels are high. This study aims to determine the relationship between lifestyle and blood sugar levels in patients with diabetes mellitus. This research design used correlation analytic with cross sectional approach. The population in this study were all patients with type 2 diabetes mellitus in the Balongrawe neighborhood, Kedundung sub-district, Magersari district, Mojokerto city, as many as 43 people. The sampling technique of this research is purposive sampling. The sample in this study amounted to 39 people. The research instrument used an observation sheet questionnaire. Data analysis using Spearman Rho test. The results showed that most of the respondents had bad diet, as many as 28 people (71.8%), almost all of them did light activities (sedentary lifestyle) as many as 35 people (89.7%), and most of them did not smoke, as many as 22 people ( 56,4%), most of the respondents had bad blood sugar levels, as many as 26 people (66.7%). The results of the Spearman Rho test showed that there was a relationship between lifestyle (diet (pvalue = 0.000), physical activity (p-value = 0.000), smoking habits (pvalue = 0.018) with blood sugar levels in patients with type 2 diabetes mellitus in Kedundung Village, Magersari District. Mojokerto City. A poor diet tends to cause blood sugar levels to increase due to the high intake of food and drinks containing carbohydrates which are eventually broken down into glucose, if not used for physical activity, blood sugar levels will be high. Smoking causes free radicals that damage insulin so that blood sugar levels are not well controlled.