In this paper, we introduce an affective variant of the Simon paradigm. Three experiments are reported in which nouns and adjectives with a positive, negative, or neutral affective meaning were used as stimuli. Depending on the grammatical category of the presented word (i.e. noun or adjective), participants had to respond as fast as possible by saying a predetermined positive or negative word. In Experiments I and 2, the words POSITIVE and NEGATIVE were required as responses, in Experiment 3, FLOWER and CANCER were used as response words. Despite the fact that participants were explicitly instructed to ignore the affective meaning of the presented words, reaction times were faster when the affective connotation of the presented word and the correct response was the same than when it differed. The results lend further support to the hypothesis that stimulus valence can be processed automatically. We also argue that the affective Simon paradigm can be used as a flexible tool for the study of affective-processing and discuss how other variants of the Simon paradigm can be developed to stimulate research on other aspects of information-processing.