Research on trust in business collaborations is generally founded on the premises that: a) cognitive trust is initially defined within contractual procedures; b) positive experiences lead to adjustments in contractual and/or informal arrangements, and c) cognitive trust is eventually supplanted by affective trust. This dynamic, process view of trust fails to capture the impact of trust experiences in external collaborations on trust emergence in a focal collaboration, and the complexity of trust co-evolution as each actor interprets and responds to the other's communication, behaviour and action. A complexity conceptualisation of trust as a self-organising, adaptive phenomenon can help us better understand the way trust develops. Through engaging with complexity theories as metaphors to enrich trust theory, trust is described as 'self-organising' as new cognitive, interpretive schema are evoked, and 'adapting' in response to trust experiences external to the collaboration. A complexity perspective evokes a new field of research questions and rich methodological opportunities.