This technical paper provides guidance on improving internal competencies for performance auditing in Poland’s public sector. It provides steps and a methodology for practitioners to follow in the various phases of a performance audit, enabling individuals involved in internal audit functions across the public sector to provide assurance that governance, risk management and internal control process are operating effectively. This guidance is designed for all public sector internal audit practitioners. It defines and differentiates performance auditing relative to other types of auditing, incorporating internationally recognised methodologies and good practice examples from other countries. It also supports internal audit functions in designing and developing further guidance to meet requirements imposed by laws, regulations and practices.