Objective The study evaluated whether a pharmaceutical care intervention can result in better understanding about hypertension, increase medication adherence to antihypertensive therapy and improve overall health‐related quality of life. Methods A non‐clinical randomized control trial was conducted whereby participants received an educational intervention through hospital pharmacists. Hypertension knowledge, medication adherence and health‐related quality of life were measured by means of self‐administered questionnaires. Descriptive statistics were used to describe the demographic and disease characteristics of the patients. Inferential statistics were used for inter‐ and intragroup comparisons. SPSS 17 was used for data analysis. Results Three hundred and eighty‐five hypertensive patients were randomly assigned (192 in the control group and 193 in the intervention group) to the study. No significant differences were observed in either group for age, gender, income, locality, education, occupation or duration of disease. There was, however, a significant increase in the participants' levels of knowledge about hypertension and medication adherence among the interventional group after completing the intervention. Significantly lower systolic and diastolic blood pressure levels were also observed among the interventional group after completion of the intervention. The interventional group, however, reported decreased yet significant health‐related quality of life at the end of the interventional programme. Conclusion Pharmacist intervention can significantly increase disease‐related knowledge, blood pressure control and medication adherence in patients with hypertension. However, further research is needed to address the decreased health‐related quality of life after completion of the study.