Objective Regular physical activity (PA) is a key element in chronic disease management. We studied the effect of a recent legislative framework given to physical activity prescription (PAP) on practices, motivations, barriers, and needs for PAP in primary care among general practitioners (GP) of the Auvergne-Rhone-Alpes region, France. Methods Our cross-sectional survey used a self-administrated questionnaire through two recruitment methods: e-mail address (online group) and face-to-face (office group). Based on the data pertaining to demography, motivation scores, needs, and barriers, we analyzed the profiles of participating GPs. Results Among the 283 GPs, online participants (n = 250) were younger than office participants (n = 33) (46 +/- 11 vs. 51 +/- 12 years, p = 0.0083), and were physically more active (80% vs 51%, p = 0.0006). Regular PA was also critical in the profile of current prescribers (OR = 2.83 (95%CI [1.28, 7.00]), p = 0.015). The motivation score for PAP was high and equal in both groups (10.5 +/- 3.3 in a maximum of 15), but multiple barriers emerged, which demonstrated age-dependent variations in the score. Young GPs mostly identified self-imposed barriers (exercise referral, PAP training), while for older GPs these barriers were equally attributable to patients. Conclusion Although the legislative framework given to PAP in France was associated with a 12% increase in the number of prescribers, PA remains poorly prescribed in primary care, even among the most motivated physicians.