Introduction: Diabetes mellitus (DM) is a serious threat to human health in the 21st century, Indonesia as a developing country has a high number of sufferers. This study aims to analyze the effect of discharge planning on the stability of blood sugar levels in type 2 patients. Methods: The design of this study was a Quasi-Experimental Pre and Post-test with a Control Group. The population in this study were all patients with type 2 DM, a large sample of 54 respondents, taken by purposive sampling technique. The instruments used are a glucometer, questionnaire, and discharge planning form. Data analysis used Wilcoxon statistical test for pre-treatment and control groups and the Mann-Whitney test for post-treatment and post-control. Results: The results of the Wilcoxon statistical test pre-post-treatment obtained = 0.000 and pre-post-control obtained = 0.093. The results of post-treatment and control group obtained = 0.009 and value = 0.05. It means that there is an effect of discharge planning on the stability of blood sugar levels in type 2 DM patients at A. Yani Islamic Hospital, Surabaya. Conclusion: The conclusion of this study is discharge planning can affect the stability of blood sugar levels in patients with diabetes mellitus type 2.