In this study, we investigate the relevance of inflectional paradigms and inflectional classes for lexical processing. We provide an information-theoretical measure of the divergence in the frequency distributions of two of the paradigms to which a word simultaneously belongs: the paradigm of the stem and the more general paradigm of the nominal class in which the stem is embedded. We show that after controlling for other variables, this measure is positively correlated with response latencies and error counts in a visual lexical decision experiment in Serbian. We interpret these results as a trace of the simultaneous influence on lexical processing of both the stem and the inflectional paradigms. (Contains 3 figures and 4 tables.)