We developed a new QSAR model, based on the optimal descriptors, calculated with simplified molecular input line entry system. These descriptors are correlated with mutagenic potential for a training set and correlated with this end-point for a test set. Statistical characteristics of the model are n = 28, r 2 = 0.902, q 2 = 0.892, s = 0.554, F = 240 (training set) and n = 20, r 2 = 0.853, q 2 = 0.823, s = 0.702, F = 105 (test set).