Cloud computing is growing at a very fast pace. Enterprise information systems (EISs) such as ERP, SCM, and CRM are used in organizations in order to increase customer satisfaction, operational excellence, and to decrease operational costs. Looking at the widespread literature available on both EIS and Cloud Computing, few researchers have examined the integration of both systems. While this area has not been fully investigated in the academia due to limited available literature, it has attracted significant interest from general practitioners. Accordingly, the Cloud-EIS can be considered as an important research problem. In this study, we attempt to investigate the factors influencing the usage and adoption of Cloud-EISs by considering Technology-Organization- Environment (TOE) framework as the basis to give directions to cloud service providers on how to design their products in order to increase adoption and usage. Analytic Hierarchy Process (AHP) is used in order to rank the determined factors. The results show that the most significant factors influencing the usage and adoption of Cloud-EISs are security & privacy, business activity-cloud EIS fitness, top management support, trust, and organization's IT resource.