Current Web services composition approaches do not take into account transactional requirements defined by designers. The transactional challenges raised by the composition of Web services are twofold: relaxed atomicity and dynamicity. In this paper, we propose a new process to automate the design of transactional composite Web services. Our solution enables the composition ofWeb services not only according to functional requirements but also to transactional ones defined using the Acceptable Termination States model. The resulting composite Web service is compliant with the consistency requirements expressed by designers and its execution can easily be coordinated using the coordination rules provided as an outcome of our approach.