We aimed to evaluate the feasibility of a tailored physical activity (PA) prescription in overweight and obese people in a tertiary hospital in Lima, Peru. A feasibility pre–post-pilot study was conducted using mixed methods. Participants received a tailored prescription scheme for PA that lasted twelve weeks. It included two prescription sessions, three follow-up phone calls, and three evaluations. Primary feasibility outcomes were recruitment, visits, and phone call adherence. Primary intervention outcomes were self-reported PA levels and the 6 min walk test. Out of 228 people invited to participate, 30 were enrolled and received the first session of prescription, 11 went to the second session, and 21 went to the final evaluation; phone call participation decreased progressively during follow-up. There were no differences in the 6th week and the 12th week compared to the baseline for all the measures, except in the 6 min walk test. The participants considered the intervention was well designed, but they suggested complementing it with dietary instructions. The prescription of PA in overweight and obese people is feasible for promoting PA, but its implementation requires refinements to anticipate possible barriers to changing behavior.