ABSTRACT Research objective: to study the possibility of using the method of chromato-massspectrometry combined with IR-spectrophotometry in the forensic chemical analysis of trace amounts of unknown poisonous and superpotent substances. Material and methods. For the forensic study a material evidence – an empty glass and a used empty disposable syringe were provided by the judicial and investigation authorities, taken from the crime scene. The following tasks were set before the experts: to find traces of any substances in the glass and syringe and reveal the origin of the poisonous and superpotent substances; determine the name of the substances. Results. During the conducted analysis using gas-liquid chromatography with the mass spectrometric detector and IR spectrophotometry, the complex method was developed for the forensic chemical examination of pregabalin and tramadol trace amounts on the object-carriers. The research established the analysis parameters such as retention time, molecular and fragmentation ions, their intensity, individual fragmentation of pregabalin and tramadol. IR spectra were obtained with characteristic passbands of functional groups related to pregabalin and tramadol structures. Conclusion. The research proved that application of the complex methods, which have high sensitivity, speed and simplicity in use, affords to quickly and accurately identify unknown substances in the composition of micro-objects.