Abstract. Nowadays web services have become one of the main technologies in the development of web applications. According to that providers now offer an increasing number of capabilities as web services. Furthermore, in the recent years, such deployment trend has seen the success of REST architecture and, consequently, the proliferation of RESTful web services. This work focuses on the semantic description of RESTful web services. It shows how the SWSAL language, already used profitably to semantically annotate SOAP web services, can be used to semantically describe a web service compliant with the REST principles. The work establishes the bases for the application of SWSAL and its related researches to the RESTful web service area.