This paper deals with the management accouting used to mark the partof the accounting that is directed at the management of a public institution. The areas of management accounting work are cost management, planning and control in executing plans and decision support. Public management has the responsibility to be organized in the fields of resource management and business management and to modernize and make the public sector more efficient. In Republic of Croatia, national budget users aren t entirely introduced to cost and management accouting and they belive that biggest contributing factor to it is lack of education and lack of workers. Insufficient use of the instruments needed to sustain cost and management accounting in public sector is reflected onto the quality of accepted decisions with all economic and financial consequences reflectedby those decisions and and that's why we point out the real need of implementing instruments needed to run cost and management accounting publicly.