The objective was to determine the effect of ageing period on beef meat from young bulls of a rustic genotype (Morucha) and an improved crossbreed (Charolais x Morucha). The ageing periods were 3, 7, 10, and 14 days. Carcass quality, pH, meat chemical composition, myoglobin content, colour, water-holding capacity, textural parameters (20%, 80% compression, and Warner-Bratzler test) and sensory characteristics were determined. Regarding carcass quality, better results were observed in crossbreed genotype than in Morucha pure breed. Myoglobin concentrations and a* values were higher in the rustic pure breed than in the crossbreed. Although no differences were observed between genotypes in cooking losses, crossbreed animals provided higher values in thawing losses. Textural parameters did not differ significantly between genotypes. For both genotypes 20% compression and Warner-Bratzler tests showed that longer ageing periods promoted more tender meat. However, sensory analysis indicated that meat from the rustic breed may require a longer ageing period than meat from the crossbreed.