Twenty males Ossimi lambs were chosen after weaned at 3 months of ages and randomly divided into 4 similar groups (5 lambs/ group) according to their initial live body weight (15.250±0.250 kg) and fed the experimental rations for 16 weeks, as an experimental periodto evaluate the utilization of cantaloupe vines hay (CLVH) in feeding growing lambs and its effect on growth performance, nutrients digestibilities, ruminal parameters, some blood parameters as well as economic efficiency. Each group was assigned randomly to feeding one of experimental rations where R1 received 60% concentrate feed mixture (CFM) +40% clover hay (CLH) and served as control ration, while the tested rations were formulated as R2: 60% CFM +30% CLH+10% CLVH (i.e. 25% in replacing of CLH), R3: 60% CFM+20% CLH+20% CLVH (i.e. 50% in replacing of CLH) and R4: 60% CFM+40% CLVH (i.e. 100% in replacing of CLH). The feed allowances were calculated according to NRC (2007) for sheep. Four digestibility trials were performed to evaluate the digestibility and feeding values of the experimental rations. Results indicated that the chemical composition of CLVH was contained 12.54, 21.64, 1.82, 41.17 and 22.83% for CP, CF, EE, NFE and ash, respectively. The digestibility of most nutrients of DM, OM, CP, CF, EE and NFE were decreased with increasing the level of CLVH in rations, but such decreases were insignificant between control ration (R1) and both tested rations (R2 and R3) over most nutrients. Feeding values (TDN and DCP) were behaved similar trends to that of digestibility of most nutrients among the experimental rations. The rumen liquor pH and NH3-N values were decreased over the three sampling times with increasing the level of CLVH up to 100% in replacing of CLH in rations. The vice versa trend was found among dietary treatments respecting TVFA´s concentration in the rumen being most changing in rumen liquor parameters did not significant. No significant differences among treatments in respect of all blood metabolites were found. Total body gain and daily gain were similar between control ration (R1) and both tested rations (R2 and R3) which have 25 and 50% CLVH on the expense of CLH, respectively, being the highest values were occurred with R2 and the lowest ones were resulted from (R4) that have 100% CLVH replacing to CLH. Feed intake, TDMI, DCPI and TDNI did not significant affected by dietary treatments, with slightly decreases in feed intake units with increasing the CLVH over the experimental rations on the expense of CLH. Concerning feed conversion measurements, insignificant differences among the dietary treatments being the best value was occurred with R2-ration (25% CLVH in replacing of CLH). Economic efficiency was tangibly improved by feeding ration that contained 25% CLVH in comparison with control one and the other tested rations. It could be concluded that feeding on ration contained 10% cantaloupe vines hay (i.e. 25% in replacing of clover hay) could be recommended for growing lambs with no adverse effects on growth performance and health state as well as being maximize the profitability.