This paper looked at the nature, merits and challenges of investigative journalism in Nigeria, with particular attention paid to newspapers, vis-a-vis the country’s Freedom of Information Act (FoIA) 2011. The objectives of the study included highlighting the merits and challenges of investigative journalism, as well as the relevance of FoIA to investigative reporting. Data for it were collected from secondary sources, while the libertarian and social responsibility media theories were deployed to guide it. It noted the merits and challenges of investigative journalism, and concluded that investigative reporting was a tough terrain for journalists, and that the media were yet to make appreciable use of the FoIA, which could ease their work as watchdogs of society. It recommended, among other things, regular training for journalists on the reporting-relevant contents of the FoIA, as well as the conscientisation of citizens on the provisions and utility of the Act, in the hope that this would promote open government for the public good.