The Accounting Standardization System for Public Administrations establishes the mandatory implementation of management accounting in Portuguese municipalities, foreseeing the disclosure of the respective information in the rendering of accounts. In this context, the main objectives of this research are to study the implementation of the Public Accounting Standard (NCP) 27 in Portuguese municipalities, with regard to the adoption of a management accounting system and the disclosure of the respective information in the rendering of accounts. To achieve these objectives, data was collected through a questionnaire. The obtained results show that 66,3% of the surveyed municipalities have already started the process of implementing NCP 27. Regarding the disclosure of management accounting information as stipulated in points 34 and 37 of NCP 27, the majority of the surveyed municipalities only disclose costs, failing to comply with the requirement to disclose information on income and results.