The article shows that despite the different legal systems of the United States and Ukraine, in the field of forensic science there is a common problem associated with the assessment of the scientific reliability of expert research and on this basis the admissibility of expert testimony. The existing Fry standard, Dober’s trilogy, Rule 702 of the Federal Rules of proof aimed at determining the admissibility of expert testimony are considered. It was stressed that the main criterion for the admissibility of expert testimony in the American proceedings was the scientific and methodological credibility of the research conducted. The validation is entrusted to the judge who performs the role of “goalkeeper”. If the previous check confirms the scientific validity of the expert research carried out, the judge “admits” the expert’s conclusions to a judge of fact to make a decision on the case. Verification of the scientific reliability of an expert’s testimony requires the judge to familiarize himself with the fundamentals and methods of the relevant sciences. Comparison of the standards of admissibility of expert research in the American proceedings with the domestic criminal procedural doctrine shows certain coincidences and differences. A significant difference between American standards is a clear prescription for judges to check and establish those properties of an expert study that determine the admissibility (scientific reliability) of an expert’s testimony. Based on the analysis of American standards, it was concluded that it is advisable in the Ukrainian procedural legislation of attaching to the subjects carrying out proof, when assessing the reliability of the conclusion and testimony of an expert. The obligation to check the scientific (the presence of general scientific provisions, theoretical foundations of a certain type of examination) and methodological (the use of a certified methodology registered in Register of expert research methods) reliability of expert research results.