In the context of collaborative networks, networked inter-organizational information systems (IOIS) play a major role by providing a shared virtual space for the informal exchange of semi-structured or unstructured knowledge. Since IT support is seen as crucial for the whole network endeavor, the perspective of system acceptance becomes important. However, discussing IS adoption at the interorganizational level brings trust into the story. Building upon socio-technical theory, this study seeks to understand the role of two dimensions of trust in the acceptance of networked IOIS. A theoretical model is developed and subsequently tested with a sample of 121 German network organizations. Network trust reveals to be important for the perceived usefulness of the system, as the main benefit comes from members’ participation. Trust in technology shows to be an even more relevant determinant for the attitude towards the system. We suggest that future adoption studies should pay more attention on the interplay of both the social- as well as the technical-relations.