Some health system in various countries in the world is highly fragmented and is unable to resolve health problems. With collaborative care system, it is expected that DM patients can be managed well. We conducted a study to determine the effect of collaborative care system on blood glucose levels of patients with type 2 diabetes mellitus. This study uses a quasi-experimental design. Data was obtained by measuring random blood glucose levels in patients with type 2 diabetes mellitus. The samples consisted of 66 diabetic patients divided into 2 groups: 35 patients in the intervention group in Puskesmas Fakfak and 31 patients in the control group in Balai Pengobatan Misi. Data was analyzed using statistical paired sample t test in the intervention group, the Wilcoxon test for the control group, and the Mann-Whitney test to compare the difference of random blood glucose levels between the groups. The results showed that the collaborative care system in the intervention group for 1 month shows the average random blood glucose levels before CCS 276.11 mg/dL and after CCS 222.43 mg/dL. Whereas in the control group before CCS 217.32 mg/dL and after CCS 266.45 mg/dL. Statistical test result showed significant differences (p<0.05) between random blood glucose levels before and after the CCS in the intervention group and the control group The conclusion of this study is a collaborative care system affects the reduction in random blood glucose levels in patients with type 2 diabetes mellitus.