In the present study, we investigated the effect of grape seed and skin supplement (GSSS), on lactating dairy ewes' production. Ten dairy pregnant ewes from northern Tunisia were allocated to two groups: control diet (C) and supplemented with 20 % ( w/ w) GSSS. The experiment lasted for 8 weeks and took place after 2 months of lambing. During the experiment, daily milk yield and milk composition were determined. Supplementation of the diet with GSSS increased milk production ( P < 0.001), calcium ( P < 0.01), free iron ( P < 0.01) and urea content ( P < 0.001) but had no effect on milk fat nor protein. From these data, it is concluded that the inclusion of GSSS in sheep diets increased significantly ewes' milk yield.