Hypertension is noted to be the easiest non-communicable disease to diagnose treat and monitor if proper health systems are put in place to ensure hypertensive drugs are accessible to hypertensive patients who need them daily. It is estimated that prevalence rate of hypertension in Kenya range from 13 % to 50 % and only 1 in 5 of the diagnosed are on hypertensive medicines. Lack of medication intake leads to uncontrolled hypertension resulting to more serious health complications which result to premature deaths. Previous studies have provided little information on the determinants of hypertensive drugs accessibility to patients. An enquiry on the availability of hypertensive drugs in public hospitals is worthwhile because hypertension has become an important social problem. This study has investigated the determinants of accessibility of hypertensive drugs by adult patients who are supposed to have uninterrupted medication intake for a healthy living. The concept of essential drugs was adopted for this study. This concept of essential drugs contained essential medicines list (EML) and the eight elements of primary health care of 1978 with a goal to ensure equal access to medicines. Descriptive design has been adopted for the study. The targeted population of 6329 hypertensive patients in public health facilities within Nairobi County. Yamane formula was used to get the sample size, which will be a total of 394 patients. Systemic random sampling procedure was employed for the study. A questionnaire tool of data collection was used for data collection. The collected data was there after coded and analyzed using Statistical Package for Social Sciences (SPSS) both for descriptive statistics (frequencies and percentages) and inferential statistics (correlation analysis). Data is presented using pie charts tables and figures. The study revealed that accessibility of medication in Nairobi city county health facilities is contributed by lack of medication in the facilities.