This research was designed to set up standard procedures for cooking battered fish portions for fast food restaurants and to study the quality of the frying fat under various conditions. Cooking time and temperature are two important factors to determine the quality of battered fish portions. Fat absorption depends on cooking time, surface area of the food, the quality of frying fats and oils and holding times. The amount of fish portions fried in a frying kettle affects the oil temperature. The addition of 0.02% ascorbyl palmitate (AP) unexpectedly reduces color development of the frying oils in simulated studies. It also reduces peroxide and conjugated diene hydroperoxide (CDHP) values and the volatile compounds, such as decanal, 2, 4-decadienal, which indicate that AP has the ability to inhibit thermal oxidation of frying fats/oils. French fries fat has lower CDHP values compared to animal fat-vegetable oils (A-V fat) in simulated studies and fried chicken oil has lower CDHP values compared to vegetable oil partially hydrogenated soybean oil (V-S oil). Peanut oil has higher thermal stability compared to the other frying fats/oils used. According to sensory evaluation, battered fish portions fried in A-V fat with no holding time are the most preferred products, while those fried in V-S oil with no holding time are the least preferred. / M.S.