The main goal of this paper is to calculate the Natural Rate of Unemployment (NRU) for Colombia for the years 2003 to 2010. It is done through the econometric estimation of an Expectations-augmented Phillips curve. The found NRU is 8.7%. This is the lowest level that can be unemployment through economic policies in the short term without generating inflationary pressures. Levels below this percentage only are possible with the implementation of structural economic policies such as training of the workforce and improving information systems in the labor market.