This Policy Brief presents the findings of the Transparency Building Initiative, a project of the Facility for Oil Sector Transparency (FOSTER) in Nigeria, implemented by CSEA. FOSTER is a five-year DFID funded project that aims to improve oil sector transparency in Nigeria through a combination of technical analysis and policy advocacy. CSEA is the local partner in the FOSTER consortium, working with Oxford Policy Management, UK, and the Revenue Watch Institute, USA. The Transparency Building Initiative (TBI) identified the most significant transparency deficits in the disclosure of information on the Nigerian oil sector. This exercise was informed by the 2010 ranking of Nigeria’s oil sector by the internationally reputed Revenue Watch Index as having ‘partial revenue transparency’. In response to this global rating of oil sector transparency in Nigeria, the TBI project sought to identify weaknesses in the discharge of statutory transparency roles by strategic regulatory institutions in the oil sector, specifically in the disclosure of information and data. The project also identified policy interventions to improve access to information on key oil sector processes and transactions.