A flock of 36 hens was fed with three different diets with two cages by diet in order to determine the effects that grass pasture accessibility and grass pasture plus chopped grass could have in front of conventional feeding provided to control and experimental groups. Controls lasted from 4 weeks of age until 18 weeks, when a sample of 24 hens (4 per cage, 8 per treatment) was sacrificed. Daily body weight gain, feed consumption, carcass yield, caecum length were recorded and fat composition was analyzed. No significant differences were found for daily body weight gain, feed consumption, carcass yield for the three groups. That indicates that in terms of zootechnical variables no advantage can be derived on having a grass supplementation when feeding meat type hens. Nevertheless, caecum length showed a very significant difference between treatments. Hens eating grass developed larger caecums (around 3.5-4 cm larger, both of them) when compared with control hens having commercial feeding. These results are linked to a higher bacterial activity and digestion associated to grass feeding, thus it can be derived that the absorption of nutrients might be different, so the fat profile stored in the hen body. Then, a different fatty acid profile is obtained, rising up linolenic acid content near to more than 20%.