Анотация: This paper describes the quantitative method of determination of chosen substances from resorcylic acid lactones group: zeranol, taleranol, alpha-zearalenol, beta-zearalenol, and zearalanone in bovine muscle tissue. The presented method is based on double diethyl ether liquid-liquid extraction (LLE), solid phase extraction (SPE) clean up, and gas chromatography mass spectrometry (GCMS) analysis. The residues were derivatised with a mixture of N-methyl-N-trimethylsilyltrifluoroacetamide, ammonium iodide, and DL-dithiothreitol (1,000:2:5, v/w/w). The GC-MS apparatus was operated in positive electron ionisation mode. The method was validated according to the European Union performance criteria pointed in Decision Commission 2002/657/EC