Compared to other areas of psychology, social cognition is somewhat indifferent to the role played by self-interest. In this paper we present a thesis that self-interest is a prominent factor shaping interpersonal perceptions and attitudes. We review several research lines showing the dominance of moral information in person perception and the dominance of competence-related information in self-perception. This research provides indirect support for the idea that self-interest strongly influences person (and self-) perception processes. We also discuss research showing directly the strong influence of self-interest considerations on interpersonal attitudes and liking as well as on more descriptive perceptions including moral judgments.