The Rappaport classification of non-Hodgkin's lymphomas was proposed almost a quarter century ago, before the advent of modern immunology. This classification, which is based entirely on morphologic features, has proved its clinical usefulness. In light of recent scientific advances, however, its terminology is not appropriate. Five new classifications have been proposed recently, each claiming to have more merit than the others. The purpose of this study is to critically analyze and evaluate these newly proposed classifications to determine which classification is conceptually and scientifically acceptable as well as clinically useful. The results of the study show that there are more similarities than differences among the Rappaport. Lukes and Collins, Dorfman, British, and WHO classifications; the Kiel classification, however, is fundamentally different (Tables 8, 9, 11). None of these classifications can be used in its proposed form. Based on the analysis of these classifications, a compromise working classification is proposed which incorporates the relevant concepts and terminology from the Rappaport, Berard, Dorfman, WHO, and Lukes and Collins classifications (Tables 15, 16). The proposed compromise classification is an attempt to reconcile the various classifications, and to stimulate others to offer modifications which may bring about a final solution to the problem of classification of non-Hodgkin's lymphomas.