Objectives: Sufficient protein intake and habitual physical activity are key factors in the prevention and treatment of sarcopenia. In the present study, we assessed habitual dietary protein intake and the contribution of animal proteins in male versus female physically active elderly and identified determinants of protein intake. Design: a cross-sectional study. Setting: the study was performed within the Nijmegen Exercise Study. Participants: physically active elderly ≥ 65 yrs. Measurements: Physical activity was assessed using the SQUASH questionnaire and expressed in Metabolic Equivalent of Task hours per week (METhr/wk). Dietary protein intake was determined using a validated food frequency questionnaire (FFQ). Multivariate linear regression analysis was used to determine whether age, sex, educational level, smoking, alcohol intake and physical activity were associated with protein intake (g/kg/d). Results: A total of 910 participants (70±4 yrs, 70% male) were included and reported a habitual physical activity level of 85.0±53.5 METhr/wk. Protein intake was 1.1±0.3 g/kg/d with 57% animal-based proteins for males, and 1.2±0.3 g/kg/d with 59% animalbased proteins for females (both P<0.05). In total, 16%, 42% and 67% of the male elderly and 10%, 34% and 56% of the female elderly did not meet the recommended protein intake of 0.8, 1.0 and 1.2 g/kg/d, respectively. Female sex (β=0.055, P=0.036) and more physical activity (β=0.001, P=0.001) were associated with a higher daily protein intake (g/kg/d). Conclusion: The majority of physically active elderly and in particular males (i.e. 67%) does not reach a protein intake of 1.2 g/kg/d, which may offset the health benefits of an active lifestyle on muscle synthesis and prevention of sarcopenia. Intervention studies are warranted to assess whether protein supplementation may enhance muscle mass and strength in physically active elderly.