Objective: To determine the productive performance and forage consumption (Trifolium repens L.) of Mexican Creole and Sasso chickens, under two rearing systems (confinement or grazing). Design/Methodology/Approach: One-hundred twenty-eight chickens (64 Mexican Creole (MC) and 64 Sasso (S)) of 35 d of age were randomly distributed in two production systems to obtain four repetitions (eight chickens per repetition) of each of the following genotype system combinations: Mexican Creole in grazing, Mexican Creole in confinement, Sasso in grazing, and Sasso in confinement. A completely randomized experimental design with a 22 factorial arrangement was used, with genotype and production system as its main factors. The following variables were evaluated: feed consumption, weight gain, and feed conversion. Additionally, forage consumption in grazing birds was determined. Results: The productive performance variables were not affected by the production system factors or by its interaction with the bird genotype. However, the genotype did influence the variables considered: the Sasso birds recorded better values (p0.05) than Mexican Creole specimens. Regarding forage consumption, no differences were observed (p0.05) between bird genotypes and, in both cases, the accumulated consumption at the 49 d of study was close to 60 g of DM. Study Limitations/Implications: It is necessary to carry out a socioeconomic study as well as a defoliation level analysis with the aim of improving the use of the resource. Findings/Conclusions: Mexican Creole birds had a lower productive performance with a similar forage consumption.