Background: Hypertension is a modifiable risk factor of mortality and disabilities around the globe. Its prevalence has been increasing in the last decade without adequate awareness and control in developing countries. Improving hypertension control is an essential strategy to prevent further Hypertension-Mediated Organ Damage. Objective: This study aimed to investigate the effectiveness of Guideline-based educational cards in controlling essential hypertension in East Borneo Primary Health Care. Method: Patients with essential hypertension enrolled in this study from February to April 2019. Patients were given a card that consists of their targetted blood pressure, blood pressure, and treatment changes during visits, lifestyle modifications, and additional information about blood pressure management. The physician orally informed all of the information in the card during the first visit. The patients were evaluated weekly and followed for total duration of four weeks. Pre versus post systolic and diastolic blood pressure were evaluated. Result: In 46 hypertensive patients, the average age was 57 years old, with 72% were females. 54% of patients had a normal Body Mass Index, and 28% were obese. Diabetes Mellitus presented as another comorbidity in 24% of patients, and only 4% of patients were active smokers. Pre-intervention systolic and diastolic blood pressure was 152 ± 12 mmHg and 90 ± 8 mmHg, respectively. Evaluation of post-intervention blood pressure outcomes revealed a significant reduction by 18 mmHg and 9 mmHg in systolic and diastolic blood pressure (p < 0,0001). Conclusion: In conclusion, Guideline-based educational card was an effective strategy in improving blood pressure control and may become a viable approach for other Primary Health Care.