Objectives The objective of this study was to examine the diagnostic value of determining the cardiac protein that binds fatty acids (H-FABP) in acute myocardial infarction (AMI) and to determine the specificity and sensitivity of H-FABP in relation to TnI, CK and CK-MB. Participants and methods 71 participants were included in this research: 29 participants with NSTEMI AMI and 42 control participants. Every participant was subject to detail anamnesis and also had an EKG. The concentration of TnI was measured by chemiluminescent immunoassay based on LOCI technology on Dimension EXL with LM analyzer (Siemens Healthcare Diagnostics Inc., Newark, USA). CK, CKMB i H-FABP were determined on Beckman Coulter AU 480 analyzer (Beckman Coulter Inc., Brea, USA). The results were processed by statistical MadCalc test, version 12.4.0.0. (MedCalc Software, Mariakerke, Belgium). Results The research has shown that there is a statistically important difference in the concentration of H-FABP among the tested groups. The median values for H-FABP were higher in the case of participants with NSTEMI AMI than control participants (8,66 vs 5,66; P=0,002). Through ROC analysis, it is also visible that H-FABP has a higher sensitivity in relation to CK and CK-MB (82,8 vs 48,3 vs 51,7), and also a somewhat lower specificity in relation to other markers. Positive and negative predictive value for H- FABP was PPV=59%, a NPV= 81%. 9. SUMMARY 22 Conclusion Estimation of H-FABP concentration early after the appearance of symptoms can provide useful information about the risk of AMI development in vague situations and can be used as a useful diagnostic marker for excluding AMI.