To arrive at the optimum level of Wet Distillers Grains with Solubles (WDGS) in dairy cow diets, a 120-day lactation trial, using hybrid napier (APBN-1) green fodder and paddy straw as roughage and concentrate mixture (T1, control) or WDGS @ 15 (T2), 25 (T3) and 35 % (T4) of DM requirement using 24 Jersy x Sahiwal crossbred dairy cows @ 6 cows per treatment allotted at random to one of the four treatments. The chemical composition of the WDGS for DM, CP, CF, EE, NFE, TA, Ca and P was 28.22, 36.72, 7.16, 8.74, 42.12, 5.25, 0.32 and 0.67 per cent. There was no significant difference in DMI (kg/d) and body weight change among the groups. CP and EE intakes were significantly (P<0.05) increased with the increase in the level of WDGS inclusion from 0 to 35%. Inclusion of WDGS from 0 (T1) to 35% (T4) of DM requirement increased (P>0.05) milk yield (4.74 to 5.8 kg/d), 4% FCM (5.39 to 7.04), % fat (4.99 to 5.52), fat yield (0.23 to 0.31 kg/d), protein yield (0.17 to 0.20 kg/d). Feed cost per kg FCM has decreased (P>0.05) from Rs.23.95 (T1) to Rs.19.76 (T4). Mean MUN (mg/dl) lower (P<0.01) in T2 (17.67), when compared to other treatments. Based on the results of the study it was concluded that WDGS can be included up to 35% of DM requirement for profitable milk production in crossbred dairy cattle rations.