This study was conducted to investigate the effect of inclusion dried taro waste (DTW) without or with dried yeast (DY) in sheep rations on digestibility, rumen fermentation activity, blood parameters and growth performance of Ossimi lambs. Comparative feeding trial was applied with twenty four growing male lambs, averaging 21.5±2 kg of body weight where they were randomly divided into four similar groups (6 each) for feeding period of 150 days. The experimental rations were formulated as followed: 65% CFM+17.5% rice straw (RS) +17.5% DTW (R1); 65% CFM+17.5% RS+17.5% DTW with dried yeast (R2); 65% CFM+35% DTW (R3) and 65% CFM+35% DTW with dried yeast (R4). Dried yeast (Saccharomyces cerevisiae) was added at the rate of 5g/h/d. Digestibility trials were conducted with Ossimi rams to evaluate the digestibility and feeding values of the experimental rations. Results indicated that most nutrient digestibilities were markedly improved with the higher level of DTW in rations, where R3 and R4 had the highest (P<0.05) digestibility values for most nutrients versus those of the lower DTW ration, without or with DY (R1& R1). Feeding values expressed as TDN did not significantly differ among the experimental rations, while DCP values were significantly improved with increasing the level of DTW, without or with DY. Addition of DY to R2 and R4 rations had no significant effect on feeding values expressed as TDN and DCP. Results of rumen liquor pH values were almost insignificant increased with increasing the proportion of DTW in rations without or with DY. Also, there were no significant differences in NH₃-N and TVFA´s concentrations among the experimental groups, with the best values being occurred with the low level of DTW-ration with DY additive (R2). No significant differences were observed among experimental groups concerning the all blood parameters except for albumin that was significant higher for animals fed ration contained only DTW with yeast (R4), while the differences respecting this item did not significant among the other treatments. Average daily gain was significantly higher with tested ration R2 than that of R3 or R4, but insignificant higher than that of R1- ration. Daily DM intake was nearly comparable among groups. The best values of feed conversion and economic efficiency were observed with lambs fed ration that contained DTW + RS + DY (R2) while; these items did not improve with increasing DTW level. It could be concluded that DTW is a nutritious fodder ingredient for ration formulation for small ruminant. Therefore the low level of DTW (17.5%) especially with yeast is highly recommended in practical feeding of growing lambs.