The objective of this paper is to analyse the impact of Organisational Project Management Maturity (OPM3) on the Project Performance (PP). PP performed by the organisations was assessed, based on interviews to project managers. Currently, litlle evidence is found in the academic literature regarding the impacts of the Maturity Models (MM) on the PP. The results show that OPM3 provided a positive contribution to PP. Some of the interviewees stated that the adoption of OPM3 brought improvements at process level, which made it possible to define in a more appropriate way, the scope, schedule, costs, and stakeholder's communications.