Background : Diabetes is a growing problem. Based on data from IDF (International Diabetes Federation), the prevalence of diabetes mellitus worlwide is 382 million and is estimated to increase for 55% become 592 million in 2035. Amount of diabetes mellitus patients in developing country keep rising when workers change their life style become sedentary life style. Modern behavior like high calories diet, high fat diet, high cholesterol diet, smoking and alcoholism will give impact to body mass index and blood pressure that lead to several disease, such as type 2 diabetes melltus. Purpose : This research is conducted to evaluate the association between body mass index and blood pressure in type 2 diabetes mellitus patient. Method : This research is nonexperimental with cross sectional approach that done in 2 months. The sample study are 50 person having type 2 diabetes mellitus in PKU Kota Yogyakarta hospital. The study anlysis is using Spearman’s test. Result : In the result analysis with Spearman’s test, the significancy is p=0,383 (not significant) for the relation between body mass index and sistolie blood pressure, and p=0,391 (not significant) for the relation between body mass index and diastole blood pressure. Conclusion : No association between body mass index and blood pressure in type 2 diabetes mellitus patients in PKU Kota Yogyakarta hospital.