Background: Hypertension remains a major public health challenge and cause of morbidity and mortality globally. Patients’ knowledge of hypertension among other factors could influence their practice of hypertension control measures. Purpose: This study aimed to determine the knowledge and practice of hypertensive patients towards hypertension control as well as identify factors influencing the practice of hypertension control in the University of Port Harcourt Teaching Hospital (UPTH), a tertiary healthcare institution in Nigeria. Materials and Methods: This cross-sectional descriptive study was carried out at the University of Port Harcourt Teaching Hospital (UPTH). One hundred and twenty (120) consenting hypertensive patients attending a clinic at the outpatient department were recruited for this study. A pre-tested structured questionnaire incorporating sociodemographic characteristics and questions on knowledge, practice and factors affecting hypertension control was administered to the patients. Data obtained was presented using frequencies, percentages, mean and standard deviation. Spearman rank correlation was used for correlation analysis of data. Statistical significance was set at p<0.05. Results: Study participants demonstrated good knowledge with a mean knowledge score of 3.68±0.30. However, poor practice in the control of hypertension with a mean practice score of 2.59±0.48 was observed. Financial constraint was identified as the factor affecting the practice of hypertension control among hypertensive patients (mean score 3.09±0.66). There were statistically significant positive correlations between mean practice score with age (r=0.269, p=0.005) and educational status (r=0.232, p=0.017). Significant negative correlations between the mean practice score and financial constraint (r= -0.246, p=0.011), negative side effects of drugs (r= -0.318, p=0.001), herbal medicine use (r= -0.207, p=0.034), failure to remember (r= -0.225, p=0.020) as well as perceived absence of symptom (r= -0.261, p=0.007) were observed. Conclusion: Hypertensive patients attending clinics at the outpatient department of UPTH demonstrated good knowledge of hypertension though this did not translate to good practice in hypertension control. Poor practice in hypertension control was associated with age, educational status, financial constraint, a side effect of drugs, herbal medicine use, failure to remember and perceived absence of symptoms.