In this study, stream trout (Salmo trutta), caught from the Northern Firat river basin. in province of Erzurum were fed trout feed after a week long adaptation period. After 2 months adaptation period, they were fed commercial trout feed regularly for 3 month trial period. Individually tagged fish were categorized as small (20-50 g), medium ( 50-100 g) and big size (100-400 g). Growth performances of groups were compared according to this classification The trial lasted end of the 3 months (91 days). The trial concluded that the group classified as big size had the highest specific growth rate with 0.31+/-0.210%. Groups classified as medium (0.10+/-0.170) and small size (0.19+/-0.180) had the lowest specific growth rate. The difference in specific growth rate was statistically significant (p<0.05) and in favor of the big size group. As a result, adaptation studies conducted on the culture of these types of trout conclude that fish weighing >100 g should be cultured as breeding candidate as they have better adaptation capacity under culture conditions.