In this study, the effects of gibel carp meal (GFM) application as a protein source on growth performance, fillet composition, feed digestion and haematological and serum biochemical indices of rainbow trout (Oncorhynchus mykiss) were evaluated. Replacement of anchovy fish meal (AFM) with GFM was performed at 0%, 50% and 100% levels (GFM(0), GFM(50) and GFM(100)). After 60 days of feeding the best nutritional performance was obtained in the GFM(100) group. There was no significant difference in crude moisture, crude protein, crude lipid or crude ash contents in fish fillet between the GFM(0), GFM(50) and GFM(100) groups. No side effects were observed in hematological and serum biochemical indices of rainbow trout. Dry matter, crude protein and crude lipid digestibility coefficients did not differ significantly in experimental groups. As a conclusion, the results of the study suggested that the GFM could be used totally as a replacer of AFM in diets for rainbow trout without the adverse effects on growth performance, feed use, feed digestion, hematological and serum biochemical parameters of fish.