Knowledge of a healthy way of life remains one of the cornerstones for the management of cardiovascular diseases at all levels of the disease course in order to reduce out-of-pocket expenses and minimize complications for overall quality of life. This study assessed the knowledge of respondents with cardiac conditions in a tertiary health care centre using a quasi-experimental design. An adapted WHO-STEP wise approach to the non-communicable disease risk factor questionnaire was used to elicit information from participants in the study. Data were analyzed using descriptive tools and results were presented in tables depicting frequencies, mean, and percentages. Findings show that 56.7% of the participants were females, 43.3% were males, and their overall mean age was 43 years ±6. Similarly, 60% were married, 30% were single, 76.7% had up to secondary education and 43.3% were artisans. The proportion of cardiac diagnoses among the participants was; hypertension (46.7%), heart failure (20%), cardiomyopathy (13.3%), atherosclerosis (10%), and hyperlipidemia (6.7%) while other diagnoses such as atria-fibrillation and heart block were just 3.3%. Knowledge of cardiac conditions and lifestyle modification was poor prior intervention (x ̅= 1.63) and ((x) ̅= 1.38) but significantly improved post- intervention (x ̅= 2.87) and (x ̅= 2.82) respectively. The study concluded that many clients were not having adequate knowledge needed to manage their health conditions effectively as a first-line therapy hence, it was recommended that adequate health information and counselling should be provided to clients at first contact to enhance efficiency of other therapies. Keywords: Cardiac Clients, Cardiovascular Diseases, Knowledge, Lifestyle Modification, Therapy