Digestibility is essential to determine the value of a forage perennial ryegrass variety. We observed a large variability for Organic Matter Digestibility (OMD) in a panel of 580 perennial ryegrass genotypes when harvested at heading date. This variability was explained by the proportion of blades and by both, the cell wall content (NDF content) and its digestibility (NDFD). These last two traits showed no correlation in this experiment. The broad sense heritabilities of OMD, NDF content and NDFD were 0.77, 0.76 and 0.73, respectively. Blades showed slightly higher OMD than ‘stems’ (sheaths and flowering stems) but the distributions overlapped largely with some ’stems’ showing higher OMD than some blades. These findings for the whole collection were also obtained within maturity groups and are encouraging for breeding for high OMD via a decrease of NDF content and an increase of NDFD in both blades and ‘stems’.