Background: Chronic diseases like hypertension need comprehensive lifetime management. This study assessed clinical and patient-reported outcomes and compared them by treatment patterns and adherence at 6 months among uncontrolled hypertensive patients in Korea. Methods: This prospective, observational study was conducted at 16 major hospitals where uncontrolled hypertensive patients receiving anti-hypertension medications (systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg) were enrolled during 2015 to 2016 and studied for the following 6 months. A review of medical records was performed to collect data on treatment patterns to determine the presence of guideline-based practice (GBP). GBP was defined as: (1) maximize first medication before adding second or (2) add second medication before reaching maximum dose of first medication. Patient self-administered questionnaires were utilized to examine medication adherence, treatment satisfaction and quality of life (QoL). Results: A total of 600 patients were included in the study. Overall, 23% of patients were treated based on GBP at 3 months, and the GBP rate increased to 61.4% at 6 months. At baseline and 6 months, 36.7 and 49.2% of patients, respectively, were medication adherent. The proportion of blood pressure-controlled patients reached 65.5% at 6 months. A higher blood pressure control rate was present in patients who were on GBP and also showed adherence than those on GBP, but not adherent, or non-GBP patients (76.8% vs. 70.9% vs. 54.2%, P < 0.001). The same outcomes were found for treatment satisfaction and QoL (P < 0.05). Conclusions: This study demonstrated the importance of physicians’ compliance with GBP and patients’ adherence to hypertensive medications. GBP compliance and medication adherence should be taken into account when setting therapeutic strategies for better outcomes in uncontrolled hypertensive patients.