Background. Development of modern aquaculture and the increasing consumer demand provoke improvements in the complex breeding technologies of economically valuable fish species. Wels catfish, Silurus glanis L. (known also as the European catfish), because of its breeding and consumption values, becomes an increasingly common object of breeding. The objective of the presented work was the evaluation of selected feeds differing in dietary lipids levels applied in rearing the wels catfish fry under controlled conditions. Materials and methods. The feeding trial (60 days) was carried out with the wels catfish fry, weighing on average 55 g. The experiment was conducted under controlled conditions in an aquarium hall in 60-L flow-through tanks. During the growth test, the fish were given four commercial feeds of the same protein amount (45%) and graded fat levels (15%, 20%, 25%, and 30%). In the final evaluation of the feeding tests, the following rearing effectiveness indices were used: food conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), protein retention (PR), lipid retention (LR), and survival rate (SR). Conclusions were drawn on the basis of statistical analysis using Statistica computer software. Results. The wels catfish fed 20%-fat-content feed attained the highest individual weights. The other treatments yielded statistically significantly lower (P