Introduction: Means of addiction, drugs are natural or synthetic substances with psychoactive effects that are being abused due to a sense of pleasure leading to the repeated taking which at one time can get out of control. A major issue in detecting and determining psychoactive substances is the constant occurrence of new compounds and substances. Today, most of the laboratories for the analysis of psychoactive substances in biological samples use immunochemical techniques as screening methods, and for validation various chromatographic techniques. Objective: The aim of this paper was to describe and compare screening and confirmatory methods in the biological urine samples. Materials and methods: The materials used and included in this paper are urine samples which are a part of the archives of the Central Laboratory of KBC Split and the Laboratory for Chemical Toxicological Analysis, Clinical Department of Judicial Medicine, Department of Pathology, Judicial Medicine and Cytology KBC Split. The initial screening technique used is an immunochemical method, most commonly labeled with an enzyme that requires verification due to its insufficient specificity. As a gold standard, a gas chromatographic method with a mass spectrometer was used which confirms a positive finding and excludes negative ones. Results: By comparison of results made by preliminary and confirmable methods deviations were observed. A sample of choice for analyzing means of addiction is urine. The analytic method of choice, at the same time the gold standard is gas chromatographic mass spectrometry. Keywords: means of addiction, urine, immunochemical methods, GC-MS