In the paper there have presented results of the analysis of small blood samples taken routinely from 3 cases after car accidents and 1 rapist. Fluorescence polarisation immunoassay (FPIA, Abott) was used for screening examinations of narcotics from the group of both opium and cocaine alkaloids, barbituric acid and benzodiazepine and also drugs from the group of tricyclic antidepressants. Confirmation of the obtained results and full identification of the substances analysed were carried out by liquid chromatography with mass spectrometry (LC-MS). In the causes of car accidents components of "compote" were found (poppy straw extract) morphine and codeine (1 case), cocaine (1 case) and also tramadol and diazepam (1 case) were also found. In the rapist methylenedioxymethamphetamine (MDMA) was determined.