Among all Latin american countries, Colombia and Venezuela are the closest, for reasons as much historical as geographical and cultural. However, profound constitutional reforms in the two countries, completed during the 1990s, conflict on many levels. The health care system, a critical stake in both reforms, exemplifies this divergence: inspired by the reform of the American health care system, the Colombian reform reserves a central place for private insurers, whereas the Venezuelan reform claims to be the anchor of « 21st century socialism » and the re-engagement of the State in the health care system. Though very different, each model has allowed for measurable improvement in health indicators, without being able to resolve the deep contradictions to which they are subjected.