The current paper discussed the reform of intelligence services in modern Mexico. In terms of background, it provides an overview of the origin of the current political system, looking back to 1917, when the current Mexican Constitution was enacted. The paper is composed of three parts, dealing with the origin and evolution of Mexican intelligence, the constitutional and legal reforms introduced after the year 2000, and a summary of the structures and processes subject to oversight. The paper ends with conclusions detailing the challenges still faced with respect to intelligence oversight.