One of the key challenges of adopting cloud computing is related to trust. Trust is necessary for effective collaboration between customers and providers and reducing transaction costs, however, in practice this trust is often lacking. From the scientific literature, it becomes clear that there is still a lot of ambiguity about trust in cloud services and that it is unclear which factors influence this trust. Hence, the research question is defined as: which factors influence the trust of an organisation in a cloud service? In order to answer this, first, an analysis of the concepts of cloud computing and trust, and the integration of those concepts in scientific literature is performed. From this analysis, a conceptual model is derived. This conceptual model is then evaluated with a Q-method study on the potential factors influencing trust in cloud services. In general, security, privacy, transparency and the willingness to change the organisation are found to be important factors. Besides the general viewpoints, there are also viewpoints specific to the three perspectives. Techno-optimist perceive technological advantage and interoperability as important, responsibility-shifters perceive contracting and accountability as important and the operational-conservatives perceive technological advantage and reliability as important. The OPF Framework as proposed in this thesis uses these perspectives in combination with the different parts of the organisation: strategic apex, cloud service management, operational IT department and cloud experts. By addressing the main concerns of the specific part of the organisation, in combination with the relevant perspective, it is possible to improve the trust of an organisation in a cloud service.