The extent and degree of myocardial injury after an ischemic event are strong predictors of patient's outcome. After acute infarction delayed contrast enhancement magnetic resonance imaging allows clinician to distinguish between viable and non-viable myocardium and can delineate with high precision the infarcted tissue. The aim of this study is to provide a quantitative method based on the fuzzy k-means clustering to assess the location and the size of the infarcted area. Segmental infarct size was visually assessed on a 4-point scale for the 208 segments. The agreement between visual and quantitative analyses was good: 82% of segments were categorized similarly by quantitative and visual analyses.