The aim of this study was to assess the effects of the four most used anaesthetics in European aquaculture MS 222, clove oil, 2-phenoxyethanol and Propiscin on barbel (Barbus barbus). The effects of anaesthetics were assessed based on haematological profile, biomarker of oxidative stress and antioxidant enzymes. This study contributed to the expansion of knowledge on the safety of tested anaesthetics and selected safe anaesthetics for barbel. Barbels were exposed to a 10-minute anaesthesia with MS 222 (in recommended concentration 100 mg×l-1), clove oil (in recommended concentration 33 mg×l-1), 2-phenoxyethanol (in recommended concentration 0.4 ml×l-1) and Propiscin (in recommended concentration 1 ml×l-1). The effects of anaesthetics were evaluated immediately after 10 min. anaesthesia and 24 hours after anaesthesia. Anaesthesia with MS 222, clove oil, 2-phenoxyethanol and Propiscin had no significant effect on haematological indices, level of oxidative stress (TBARS) and activity of glutathione reductase in barbel tissues. The activity of catalase was significantly increased in the muscle 24 h after anaesthesia of all anaesthetics compared to the control. Superoxide dismutase activity was changes in all experimental groups (immediately after 10 min. anaesthesia and 24 hours after anaesthesia). The tested anaesthetics not altered hematopoietic tissue and had not effect on the level of lipid peroxidation in barbel´s tissues. The results of this study suggest that the antioxidant systems of barbel are altered by Propiscin anaesthesia, but they are slightly affected by MS 222, clove oil, and 2-phenoxyethanol anaesthesia. On the basis of the results of this thesis, for anaesthesia of barbel we can recommend clove oil and 2-phenoxyethanol as an alternative MS 222.