What are the determinants of an organization’s decision to adopt Service-Oriented Architecture (SOA)? Although the paradigms of service orientation and SOA have become quite omnipresent in the IS literature, research is still lacking to provide a comprehensive view upon drivers and inhibitors of the organizational decision to adopt SOA. Based on the mature strand of adoption research, this paper develops a conceptual model in order to increase the understanding of the determinants influencing this decision. Thereby, the drivers and inhibitors are distinguished in organization-specific and innovation-specific factors. The organization-specific factors cover two aspects: (1) the compatibility of technology and organization (i.e., SOA expertise of the employees, management support for SOA, IT/ Business alignment, degree of process documentation) and (2) management fad and fashion. The innovation-specific factors cover the perceived benefits, perceived complexity, and standardization of available technologies related to SOA. Beside developing this theoretical model for laying the foundation for future empirical research, a further contribution of this paper is the development of a comprehensive measurement model for SOA adoption, which differentiates between the IT and the enterprise layer.