This article develops the foundations for a theory of interpersonal trust-building based on relational signalling theory (RST). RST is based on the assumptions that rationality is bounded through framing, that preferences are partially determined by altruism (through a distinction between foreground and background goals), and that an individual's action is influenced by the normative context in which he or she operates. The focus is on interpersonal trust in work relations within organizations. Interpersonal trust-building is construed as an interactive process in which both individuals learn about each other's trustworthiness in different situations. Four conditions for the building of interpersonal trust within organizations are (1) the suspension of all opportunistic behaviour, or the removal of distrust; (2) exchange of positive relational signals; (3) avoiding negative relational signals, i.e., dealing with trouble; and (4) the stimulation of frame resonance, or the introduction of trust-enhancing organizational policies. The proposed theory can explain important characteristics of trust in organizational contexts, such as the interactive nature of trust, the learning required to build trust, the role of psychological mechanisms (such as attributions and perceptions) in decisions to trust, the limits to trust, asymmetries between trust and distrust and the context-dependency of trust. PUBLICATION ABSTRACT