In the present work, the effects and validity of poultry droppings (PD) addition to fish diet, supplemented with 3g ascorbic acid (AA)/kg diet and 10% live yeast (LY), on the production of Oreochromis niloticus were studied under different experimental conditions. Such effects were evaluated in terms of different parameters including growth performance, muscle composition, blood constituents and thyroid hormone levels. Fish diets containing four different levels of poultry droppings (10, 20, 30 and 40%) were considered and evaluated in comparison with the basal diet (the control). The dietary ascorbic acid (AA) and live yeast (LY) improved (P<0.05) body weight. Moreover, with the addition of 3gAA/kg diet and 10% LY the body weight gain and body length increment did not differ significantly (P>0.05) in fish fed the diets containing 10, 20, 30, and 40% poultry droppings in comparison with fish fed the control one. Also, AA and LY improved (P<0.01) HSI and slightly increased female GSI. Addition of AA and LY had no effect on crude protein in muscles whereas such addition reduced fat, moisture and ash percentages in muscles (P<0.05). AA and LY led to significant increase of hemoglobin, serum glucose, albumin and T3 and decrease in serum cholesterol. While, PCV%, serum total protein, globulin, A/G ratio and urea-N levels were not affected. These findings were discussed and it is concluded that the addition of ascorbic acid (AA) and live yeast (LY) improved growth performance and counteracted the increased percentage of poultry droppings added to fish diet. This make the diet with increased percentage of poultry droppings to be practically and may be one of the most suitable commercial diets for Oreochromis niloticus under subtropical environmental conditions prevailing in Upper Egypt.