In the context of New Public Management, Public Administration must be alert to the efficient management systems in order to rationalize the financial resources and disseminate transparent, accurate and consistent economic and financial information to further assess the performance of managers and organizations. The technological advances have influenced the way financial information is disseminated, including the use of the Internet, allowing it to be quickly accessed. This work is based on the assumptions of agency, public choice and signaling theories, and aims to assess the level of disclosure of financial information on the websites of local authorities in Portugal and to identify factors that may influence it. Given the results, not all local authorities disseminate all the financial information required by law on the websites. Among the factors tested, the size and political competition are the ones that seem to influence the level of disclosure of financial information on the websites. In the context of New Public Management, Public Administration should both focus on the citizen's needs, which are increasingly demanding, and promote the transparency and efficiency of public management. In this way, it should provide the public bodies not only with effective and efficient management