Aim: Heart-type fatty acid binding protein (H-FABP), an early marker of cardiac necrosis, is released rapidly from myocardium as a consequence of ischemic injury. We hypothesized that more severe and extensive coronary atherosclerosis would result in more pronounced myocardial injury and necrosis in patients with acute myocardial infarction (AMI). Therefore, we sought the relationship between serum H-FABP levels and the severity and extent of coronary artery disease (CAD) assessed using the Gensini score.Materials and Methods: Fifty patients with AMI who underwent invasive coronary angiography were divided into 2 groups according to the angiographic Gensini score, namely the moderate to severe CAD group (group 1) and the mild CAD group (group 2). A point of care test and Cardiodetect Quant device were used to detect whether H-FABP was positive and the quantitative measurements. The data obtained from this study were evaluated using the PASW statistic programme.Results: Mean serum H-FABP concentration was significantly higher in group 1 when compared to that in group 2. Furthermore, a strongly positive correlation was found between the Gensini score and serum H-FABP levels.Conclusion: The findings of our study suggest that the quantity of myocardial necrosis demonstrated by serum H-FABP levels is higher in patients with AMI who have more severe and extensive CAD. H-FABP levels are also positively correlated to the Gensini score. We propose that H-FABP, an early marker of myocardial necrosis, may also provide a clue about the severity and extent of CAD, especially in the setting of AMI.