Conceptualizing an exercise program according to exercisers motives seems to be crucial. Thus, adequate and validated scale assessing motives for physical activity is necessary. This study aimed to translate and validate the Exercise Motives Inventory-2 (EMI-2), a scale assessing fourteen motives for regular physical activity in Portuguese exercisers. In addition, comparison of motives between groups were made according to gender, age, and fitness activity. For scale validation, data from two independent samples were collected: calibration (n = 820; female = 499) and validation (n = 733; female = 451) participants. For scale reliability and mean difference analysis, data from a new sample was collected (n = 515; female = 342). Results showed that data did not fit the original 51-item model. After reviewing item loadings, two items were eliminated, since they presented factor loadings below acceptable. Hence, the revised model encompassing 49-item had an adequate fit. Convergent and discriminant validity was achieved in the revised model, displaying acceptable construct validity. In addition, invariance criteria were respected between female and male Portuguese exercisers. Regarding mean comparison analysis, differences were found between gender, and across age and fitness activities. Nevertheless, in overall the majority of exercisers indicated "general health" and "physiological" motives as the most valued. The EMI-2 is a reliable scale assessing motives in Portuguese exercisers. This study suggests that exercise programs should be conceptualized considering motives, but also gender, age, and fitness activity. Keywords Exercise. Motives. Confirmatory analysis. Measurement invariance. Mean differences Physical activity and motives "What drives you to exercise?" is possibly one of the most frequently asked questions by exercise professionals and peers when someone engages in physical activity for the first time. Research on understanding the motives for individuals to choose to exercise could be of great practical value (Markland and Hardy 1993) and therefore conceptualizing an exercise program according to exercisers motives seems to be essential. Concerning exercising, goals of pleasure,