The changes in chemical composition, cholesterol and fatty acids have been determined in raw and fried rainbow trout. Olive oil, sunflower oil, corn oil, margarine and butter were used in the frying process. Moisture content was decreased and protein, fat, ash and cholesterol contents were increased after frying. Differences in moisture, protein, fat, and ash content between the samples were significant (P < 0.05). pH, thiobarbituric acid (TBA), and total volatile basic nitrogen (TVB-N) values were within the limiting depletability values. In the fish fried with sunflower oil and corn oil, an important amount of decrease (P < 0.05) was determined for myristic, palmitic, palmitoleic, stearic, linolenic, arashidic, and docosahexaenoic acid (DHA). However, an important amount of increase (P < 0.05) was determined in heptadecanoic, oleic, and linoleic acid. DHA content was decreased in all oil groups. Cholesterol level was increased with the use of butter. The lowest level of cholesterol was observed in fish fried with margarine.