Magister Scientiae (Physiotherapy) - MSc(Physio) / Chronic diseases of lifestyle (CDL) are on a raising trend in the world regardless of age,economic class or geographical location of a population. The mortality rate associated with CDL is alarmingly among the highest globally. Tanzania is not exempted from this development.Literature indicates that physical activity is a health practice that can prevent CDL. It is recommended that medical practitioners should hold the responsibility of counselling patients on physical activity. Some studies outside Africa found an association between doctors’ physical activity patterns and their counselling practices on the same. This study therefore sought to establish whether physical inactivity among medical doctors in Tanzania significantly influenced their counselling practices on physical activity. A cross sectional quantitative survey at the Muhimbili National Hospital and Muhimbili Orthopedic Institute was conducted to derive the required information. A self administered structured questionnaire was voluntarily answered by 144 medical doctors. The Statistical Package for Social Sciences (SPSS) version 17 was used for data capturing and analysis. Descriptive statistics were employed to summarize data and was expressed as means, standard deviation, frequencies and percentages. The students’t-test was used to compare mean physical activity between different groups. Furthermore students’t-test and analysis of variance tests were used to examine association between different variables. Chisquare tests were used to test for associations between categorical variables. Alpha level was set at p< 0.05. Most of the participants in this study were sedentary in their leisure time and only active at work. When their quality of physical activity counselling was assessed, the majority of them were found to be poor physical activity counsellors. A significant association was found between physical activity and age, as well as physical activity and counselling practice (p<0.05).Participants mostly informed their patients about the intensity and duration of exercising more than any other idea of physical activity such as types of exercises, issuing of a written prescription and planning for a follow up. Lack of knowledge and experience about details of physical activity were reasons offered for failure to counsel. Participants also reported the inconvenience of physical activity facility’s schedules, fatigue and tiredness to be their barriers to physical activity participation. Doctors in Tanzania lacked personal initiative to participate in physical activity and consequently lacked the motivation to counsel. Measures around enhancing this health practice should be enhanced by all stakeholders including medical doctors,physiotherapists and patients. The need for short term and long term training in matters related to physical activity are therefore necessary among the practicing doctors and those undergoing training in medical schools. Physiotherapists who are trained in movement science can offer valuable advice/information to medical doctors to ensure that medical doctors acquire physical activity prescription and counselling knowledge. Collaboration between stakeholders in campaigning against sedentary lifestyles should be enhanced. Further reasons for failure to counsel, hindrances to physical activity participation and modern approaches to counselling should be explored.