This research is concerned with the mediation of the relationship between co-creation and trust by emotions. Data is generated from responses to questions posed after panellists read a structured scenario. Emotions are found to partially mediate the relationship between co-creation and trust. The mediation effect is stronger in B2C situations than B2B, in services rather than products and for women more than men. In a services context there is full mediation of the relationship between co-creation and trust by emotions for women and for a business-to-consumer context. The strategic imperative that co-creation is vital in the services industry is underscored, particularly in a consumer situation or when dealing with women.