Background: This study aimed to research on how adherence and blood control could make a difference when it comes to develop complications. Methods: The study’s subjects were 255,916 patients who were newly diagnosed with hypertension in 2009 using data collected by National Health Insurance Cooperation. Patients are considered as a group under adherence if visit days and prescription days are more than 300 days. Patients are considered to have successfully controled their hypertension based on actual value measured by National Health Insurance Cooperation and the study takes a look at whether they were diagnosed with complications of cerebrocardiovascular disease in 2012. Chi-square test and logistic regression was used to analyze. Results: Patients who were able to control their hypertension show 0.80 times chance of developing cerebrovascular disease, and 0.89 times chance of developing cardiocerebrovascular disease. The group of adherence shows lower chance of developing complication in general than the group of non-adherence. Conclusion: The study revealed that hypertension’s constant treatment could control the blood pressure and prevent complications. It is important that encourages patients to effort for persistent treatment for reducing complication.