With the aim of developing a sustainable agronomic management for the hillside agro-system that includes traditional crops maize and beans, a research was carried out from 1996 to 1998 at two locations in the South of Veracruz, Mexico. The experiment included planting of maize intercropped with two cover crop legumes (Mucuna and Canavalia) during the summer and planting Common Bean cv. Negro INIFAP in the fall. A completely randomized design arranged as split plot was utilized, with the cover legumes as main plots and six fertilizer treatments as small plots. In biomass production Mucuna was significantly superior to Canavalia and thus as nutrimental source. Weed biomass production was 52% lower in the treatments with the cover legumes as compared to the sole maize crop. No difference was found for maize seed yield among main treatments, indicating that the cover crops did not affect maize yield. In common bean the highest yield was obtained in the Mucuna and fertilization dose of 30 kg/ha N and 30 kg/ha P2O5. In conclusion Mucuna was the best cover crop in biomass production, reducing weed competition and favored mineral nutrition in Common Bean.