Background: In 2008 Non-communicable diseases (NCDs) were responsible for 63% of deaths worldwide and 80% of these deaths occurred in developing countries. Four of them were responsible for more than 80% of mortality from NCDs, which were cardiovascular diseases, cancers, chronic respiratory diseases, and diabetes. They shared the same risk factors. Objective: To determine the prevalence of NCD risk factors in patients admitted to consult in the outpatient unit of the National Teaching Hospital of Cotonou. Patients and Methods: This was a transversal, descriptive and analytical study which took place from 15 June 2011 to 16 September 2011. It focused on 1000 subjects found after a recruitment of all patients coming to consult during the study period. The collection technique was a questionnaire followed by physical measures (weight, height, blood pressure and waist) and biological measures (fasting glucose and cholesterol). The data were analyzed with the software Epi-3.3.2 info. Results: The mainly prevalent behavioural risk factors were smoking (10.2%), alcohol consumption (60.3%), insufficient intake of fruits and vegetables (84.2%), and physical inactivity (57.6%). The prevalent physical risk factors were hypertension (47.4%), obesity (27.5%), and overweight (35.3%). The prevalent biological risk factors were diabetes (28.5%), and hypercholesterolemia (10.4%). The level of cardiovascular risk was higher than 40% in 81 people (8.1%). Conclusion: This study shows the importance of risk factors for NCDs in outpatient Unit in the National Teaching Hospital of Cotonou.