In Latin America, research on presidentialism has failed to analyze the institutional structure at the core of, and provides organizational self restraint to, the Executive branch. In this context, the Centre of Government emerges as the space where presidential decision-making takes place, reinforcing elements such as the coherence and coordination of public policies. Through the Chilean case this study aims to identify the factors that were able to alter the institutional structure of the Centre of Government from 1990 to 2010. Party discipline and institutional stability emerge as the cornerstones of the course taken by the Government Centre in Chile.