Glucosinolates are products of secondary metabolism identified in over 16 different plant families, the most significant of which is the Brassicaceae family, which includes vegetables often used in human nutrition. In plants, glucosinolates are found in special compartments separated from the myrosinase enzyme, which cleaves these otherwise chemically stable compounds into degradation products such as thiocyanate, isothiocyanate, nitrile and indole. Due to the recorded biological activity of degradation products, they have been the subject of many recent researhces. Brassica oleracea var. italica, better known as broccoli, is one of the most popular types of vegetables. Hydroponically grown vegetables sprouts for everyday consumption are being increasingly used. In this work, broccoli sprouts were grown in clean water with different concentrations of selenium: 1 ppm, 2.5 ppm, 5 ppm, 7.5 ppm and 10 ppm to monitor its influence on the glucosinolate profile. Glucosinolates were isolated, converted into desulfo-form and analyzed by UHPLC-DAD-MS/MS technique. The analysis determined the presence of 12 different glucosinolates: progoitrin, gluconapoleiferin, glucoalisin, gluconapin, glucocochlearin, 4-hydroxyglucobrassicin, glucobrassicannapin, glucobrassicin, glucoberteroin, gluconasturtin, 4-methoxyglucobrassicin and neoglucobrassicin. A dominant amount of gluconapin and glucobrassicanapin was observed with maxima of 67.31µmol/g and 36.14 µmol/g, respectively, at a selenium concentration of 5ppm. Glucoberteroin was observed only in traces. Elevated concentrations of selenium had a negative effect on the growth of broccoli and also affected the profile of glucosinolates in different samples. Two samples of broccoli sprouts grown in selenium concentrations of 5 ppm and 7.5 ppm were subjected to reaction with the myrosinase enzyme to obtain glucosinolate degradation products that were identified by GC-MS. Two nitriles were identified: benzenepropanonitrile and cyano-3,4-epithiobutane. The second goal of the experiment was to examine whether the broccoli will absorb part of the selenium in seven days due to the chemical similarity and abundance in which it grew and incorporate it into the structure of its glucosinolates. No selenoglucosinolate or selenomethionine-derived glucosinolates were detected, nor their degradation products.