The dispensation of the New Public Management (NPM) over the last two decades has provided a surest way of restructuring the administrative systems of Ghanas Public Service through reforms. Ghana after adopting its maiden NPM reform in 1987, have remained focused on its bureaucratic reformative agenda. Since 1987, Ghana has witnessed several NPM reforms with some internationally adopted and others internally initiated. It is worth noting that, the NPM reform trajectories project performance management system and reform as an integral component of all these reform initiatives. The most recent Performance Management (PM) reform in the Ghanaian Public Service, is the New Performance Management Policy (NPMP). And in this connection, the study examines the whole operationalisation of PM reforms, specifically the NPMP in the Ghanaian Public Service. In a narrow sense, it mainly explores and explains the impact and influence of leadership and administrative culture as contextual factors on the implementation and institutionalisation of the NPMP in Ghanas Public Service.