This paper studies the renegotiations of road concessions in Chile, Colombia and Peru for the period 1993-2010. First, it analyses the legal framework, the institutional design and the types of concessions of these countries and second, it uses a novel data composed of a sample of 61 of the 62 road concession contracts to explore the renegotiation of these concessions. 50 out of 61 contracts have been modified at least once, resulting in more than 540 renegotiations. All modified contracts were changed for the first time less than 3 years after the initial signing of the concession. Empirical analysis suggests that State-led renegotiations, which were more common than firm-led renegotiations, were motivated by the opportunistic behaviour of governments. State-led renegotiations that added new stretches of roads and that included additional complementary works during governments’ last year in office were costlier than other renegotiations. Finally, governments deferred a larger share of renegotiation’s fiscal costs in State-led renegotiations that took place during their last year in office.