Tropaeolum majus L. is a wild, annual, herbaceous plant from the Tropaeolaceae family. Glucosinolates are a unique and important group of secondary metabolites in some plant species. Glucosinolates are chemically stable until they come into contact with the enzyme myrosinase (β-thioglucoside glucohydrolase). They are hydrolyzed into a number of biologically active compounds. The enzyme myrosinase catalyzes the hydrolysis of the thioglucosidic bond, i.e. it enables the cleavage of the bond between sulfur and glucose in glucosinolates, which leads to the release of glucose, sulfates and aglycones. In the plant, myrosinase is present in idioblasts of abnormal shape, size and content, which are called myrosin cells. The aim of this research was to investigate the positive expression of the enzyme myrosinase type 1 in the area of the root, stem and leaf of the nasturiun through different developmental stages after the plant has emerged. In this work, basic histological techniques of plantderived tissue were used, as well as immunohistochemical and immunofluorescent staining of the nasturtium tissue. A positive immunofluorescence signal of the enzyme myrosinase was observed in all investigated parts of the plant, through all four developmental phases in myrosin cells or as scattered cells in the ground and vascular tissue. The strongest positive immunofluorescence signal was observed in the idioblasts of the ground tissue of the root.