This chapter reviews the main transparency-related initiatives that have been developed and implemented in the local government context in Portugal, over the last 40 years. A critical discussion on these landmarks allowed concluding that, in order to be effective in what concerns transparency and accountability, initiatives need to combine administrative and legal reforms with automatic data disclosure, embedding reporting mechanisms in already existing processes, and incorporating frameworks to regularly monitor the results. Another major recommendation could finally be derived from this analysis: it is necessary to put in place a comprehensive set of principles regarding transparency mechanisms, to be included, at a very early stage, in every Public Administration innovation programme. Transparency should be a concern when developing such programmes, as it is efficiency and effectiveness.