OBJECTIVE: Physical activity is suggested to play a key role in the prevention of several chronic diseases. However, data on the association between physical activity and multimorbidity are lacking. METHODS: Using data from 1007 men and women aged 65-94years who participated in the population-based KORA (Cooperative Health Research in the Region of Augsburg)-Age project conducted in Augsburg/Germany and two adjacent counties in 2008/09, 13 chronic conditions were identified, and physical activity scores were calculated based on the self-reported physical activity scale for the elderly (PASE). Multivariable sex-specific logistic regression was applied to determine the association of the continuous physical activity score with multimorbidity (≥2 out of 13 diseases). RESULTS: Physical activity (mean PASE score±SD) was higher in men (125.1±59.2) than in women (112.2±49.2). Among men, the odds ratio (OR) for multimorbidity was 0.73 (95% CI: 0.60-0.90) for a 1 standard deviation increase of the PASE score. No significant results could be observed for women (OR: 1.05; 95% CI: 0.83-1.33). CONCLUSION: We demonstrated an inverse association between physical activity and multimorbidity among men. Further prospective studies have to confirm the temporality of effects.