This study researched the degree to which the growth of rainbow trout (Oncorhynchus mykiss) was influenced by pellet feed made from silage produced from waste generated by the fish food processing industry. During the 90 day trial, a completely random parcel method was used with three repetitions. The average weight of the rainbow trout was 54.05 +/- 235 g, while their average length was 17.46 +/- 0.11 cm. One hundred (100) trout were stocked (25 kg/m(3)) in each fiberglass fish feeding tank. Four different experimental groups were formed; feed without silage (control) and pellets with 25, 50 and 100% silage. Fish were fed twice per a day until they were satisfied (ad libitum). At the end of the study, the group that was fed with feed made from 50% silage increased the most in weight, followed by the control group and the groups fed with 25 and 100% silage, respectively. The average weight differences between the groups were found to be significant (P<0.05). In conclusion, it can be said that replacing the fish meal in food used to feed trout with 50% fish silage has a positive effect on growth, and that silage can be used in trout food at the aforementioned ratio.