In this article we report on the design, prototyping and results of a research effort aimed at identifying if and how trust affects the creativity of a partnership between two economic agents. The methodology combines an experiment and two questionnaires. The purpose of the research is to increase our understanding of trust and its impact on the outcome of cooperation, and to derive some guidance for economic actors, namely R&D managers and executives who want to build trustful innovation oriented relationships with their business partners. Specifically, we investigate the effect of trust on partners' creativity and willingness to invest financially in a joint development. Our results show that more trustful partners invest higher amounts in the alliance, while there seems to be an optimum amount of mutual trust between partners to maximize their joint creativity; if the level of mutual trust is below or above this threshold; their joint creativity seems to decrease.