One of the most important element in the analysis of public administration's performances is the management. In fact it is the connection point between objectives (fixed at political level) and the system of outputs and outcomes, achieved by public personnel at different levels. This is the main reason why during the last decades, the reform of Italian public administration has concentrated on improving public action performances, by a regulation of public management and the connected introduction of two key words: autonomy and accountability. This means that managers should be endowed of greater autonomy in the execution of their managerial activities and, at the same time, they are fully responsible for both personnel's and whole body's performance. Even thought the legislative decrees nr. 286/99 (art.5) and nr. 165/01 (art.19-21) introduced an evaluation and control system of managers' activities, they have been applied with a very little success inside public administration. The reason is that evaluation has been realized in a bureaucratic way, often by the use of a great number of general indicators, which do not concretely reflect actual organizational processes and related outcomes. According to the above considerations, it could be stated that the reform of the Italian public administration did not completely accomplish its two fundamental goals. First of all, it did not recognize a greater autonomy to managers, considering that in the Italian system there are many instruments which can be used by politicians to affect managers' executive action and, on the other hand , it has provided a managers' performance evaluation system which is not compliant to the reality. However, according to these themes, a new discipline has been recently provided by the legislative decree nr. 150/09. Its aim is to introduce a concrete system of measures and indicators, which are oriented to ensure the accountability of public managers' activities. The purpose of this paper is to verify why managers' performance evaluation system provided by legislative decrees nr. 286/99 and nr. 165/01 was not proper and well-functioning; to analyze the changes introduced by the new discipline and, finally, to verify if such innovations are really able to realize an adequate evaluation system of public managers' performances, in order to built a strong feedback flow for the review of personnel policies.