This research report evaluates Nigeria’s implementation of its open contracting commitment under the first National Action Plan (NAP I) of the Open Government Partnership (OGP), spanning January 2017 to June 2019. The commitment aimed to improve transparency, accountability, and efficiency in public procurement through the adoption of the Open Contracting Data Standard (OCDS). By assessing milestone activities and performance indicators, the study explores how far Nigeria progressed in making procurement data open and accessible. Findings show that implementation was partial at best. The creation of the NOCOPO portal—a central procurement database—was delayed, underutilized, and poorly populated by Ministries, Departments, and Agencies (MDAs). Despite the potential of the platform to support procurement reform, its lack of functionality and limited awareness significantly hindered its impact. Similarly, open competitive bidding practices remained minimal, and transparency gaps persisted due to weak stakeholder coordination and the absence of a National Procurement Council. The report concludes that while the commitment introduced critical tools for reform, execution was stifled by institutional inertia, legal limitations, and inadequate digital infrastructure. It recommends stronger political will, enhanced technical capacity within MDAs, and robust legal backing to enforce open contracting measures. These insights are key for shaping more effective implementation under Nigeria’s subsequent OGP action plans.