The aims of this study were to assess and compare declared and real volume of physical activity (PA), and to evaluate correlations of these measurements with glycemic control (HbA1c) and body mass index (BMI), in patients with type 2 diabetes mellitus (T2DM).A group of 31 (16 women and 15 men) type 2 diabetic patients treated with insulin monotherapy, from (mean age=54±3.6 years, BMI=29.7±4.8kg/m 2 , T2DM treatment=9±8 years, HbA1c 7±1%) and not professionally active (unemployed or retired) was recruited.An assessment of energy cost (EC) of their weekly PA using International Physical Activity Questionnaire (IPAQ), and an accelerometer assessment was performed.Total energy expenditure of the declared weekly PA, calculated from the IPAQ (DPA) was 2513±1349METmin/week, and 2428±1348, for male and female participants, respectively (p>0.05). EC of the real PA (RPA), registered with the accelerometer was 4552±2028kcal/week, and 4032±2288kcal/week, for males, and females, respectively. Patients who demonstrated a high DPA, based on their IPAQ score, showed a significantly higher RPA, as registered by the accelerometer (p<0.05). HbA1c and BMI did not correlate with their PA measurements.Our findings indicate that the IPAQ may serve as a potential tool for physical activity assessment with no further requirement for more sophisticated methods. Our results suggest that habitual physical activity has no impact on glycemic control and BMI in type 2 diabetic patients. However, further studies on a larger population are needed to explore these issues.