Antihypertensive medication is one way to manage hypertension but many hypertensive patients do not optimize drug therapy to achieve blood pressure control. Hypertensive medication non-adherence continues to become a contributing factor to hypertensive complications like heart attacks, heart failure, stroke, kidney disease. Prevalence of non-adherence to antihypertensive treatment is not known but it’s thought to be increasing. Associated factors of non-adherence are complex, are both internal and external to the patient but are difficult to extrapolate. This can partly be because the determinants of non-adherence to hypertensive may have a locality effect due to many factors such as culture and health system in a given locality. Hence, studies from one region may not have a cross-application. Therefore, there is the need to study the factors associated with non-adherence at a local scale. Descriptive study design was adopted to guide the implementation of the study. The population comprised of 575 people among doctors, pharmacists, nurses, record officers and hypertension patients. The respondents were identified through simple random sampling and a sample size of 81 patients was achieved and 10 health care providers including doctors, pharmacists, record officers and nurses were also interviewed through census method. Data was collected between the month of April and May 2019. Questionnaires were used as data collection tools for the patients while the interview schedule was conducted to health care providers through an interview guide. Descriptive and inferential statistics were used for data analysis, aided by SPSS. The study revealed a significant negative correlation (r_pb = −0.227, p < 0.05) between age and non-adherent, insignificant relationship with marital status (r_pb = −0.129), insignificant (r_pb = −0.064) correlation with patients’ level of education and a positive correlation with monthly income (r_pb = 0.24). A majority of patients stated that (64%) of the hypertensive patients had missed medication. Patient-related factors: cost of medication, religious beliefs, age of the patient, their education level, preference to traditional medicine, and sociocultural factors together were found to be significant predictors of non-adherence to hypertension medication, χ²= 17.14, df = 1, N = 81, p < 0.05. However, it’s only age (p = 0.01), religious beliefs (p = 0.04), and cost of medication (p < 0.05) that were individually, significant predictors to non-adherence. Non-adherence to hypertension medication is a major problem at Chuka Level Five Hospital. This was due to lack of funds, time, forgetfulness and patient thinking that they had healed thus continuous follow-ups to improve adherence, positive reinforcement to increase motivation in order to address forgetfulness, and supply of constant and subsidized hypertensive drugs to the hospital are necessary to prevent patients from missing the drugs. There is need to reduce out of pocket payment through establishment and strengthening of the community health insurance scheme. The study recommends that the hospital should set aside some resources for making patients’ follow-ups especially those were treated and left to go home; discussions be made with patients on severity of non-adherence and importance of adherence; use of positive reinforcement to increase motivation and mechanism to be put in place to subsidize the cost of medication.