The present study aimed to study the effect of incorporation of increasing levels of fermented fish silage (FFS) as a substitute of fish meal (FM) in the diets of Nile tilapia (Oreochromis niloticus) fingerlings. The highest average body weight, BW (40.14 g) was recorded for control group which fed the control diet (FFS0) followed by those fed the diet FFS25 (39.35 g) and the difference between these two groups was not significant. Compared to fish fed the control diet the other replacing levels of FM by FFS (FFS50, FFS75 and FFS100) significantly (P