Disclosed are methods of inspecting semiconductor wafers, inspection systems for performing the same, and methods of fabricating semiconductor devices using the same. A method of inspecting a semiconductor wafer including preparing a wafer including zones each having patterns, obtaining representative values for the patterns, scanning the patterns under an optical condition to obtain optical signals for the patterns, each of the optical signals including optical parameters, selecting a representative optical parameter that is one of the optical parameters that has a correlation with the representative values, obtaining a reference value of the representative optical parameter for a reference pattern, and obtaining a defect of an inspection pattern by comparing the reference value with an inspection value of the representative optical parameter for the inspection pattern.