Fish protein hydrolysate (FPH) has shown immense potential as a dietary protein supplement and immunostimulant in aquaculture, especially in Nile tilapia production. Four isoproteic diets (30% crude protein) were prepared by including FPH at varying percentages (0%, 0.5%, 1%, and 2%). Nile tilapia fed with FPH diets for 90 days, and their growth performance, feed utilization, blood biochemistry, liver and gut morphology, and resistance against Streptococcus iniae were investigated. The findings revealed that diets physical attributes such as pellet durability index and water stability were remarkably (p p p p p p