Resumen La mayor parte de la evidencia empirica sobre el Efecto de o Hipotesis de Fisher, sostiene que la relacion entre la tasa de inflacion y la tasa de interes nominal debe ser igual a uno. Este documento analiza la relacion entre la tasa de interes nominal y la tasa de inflacion, para la economia de Colombia, durante el periodo comprendido entre 1990M1 - 2010M12. Se presenta evidencia empirica sobre la existencia de una relacion de largo plazo positiva entre la tasa de interes nominal y la tasa de inflacion para Colombia. Adicionalmente, se aplica una prueba de cointegracion con cambio de regimen desarrollada por Gregory y Hansen (1996), la cual permite presentar evidencia estadistica de la existencia de un cambio estructural en esta relacion hacia finales de los anos noventas. Abstract Most of the empirical evidence on the or holds that the relationship between inflation and nominal interest rate must be equal to one. This paper analyzes the relationship between the nominal interest rate and inflation rate, known as the Fisher Effect or Fisher hypothesis for the Colombian economy during the period 1990M1 - 2010M12. We present empirical evidence on the existence of a positive long-run relationship between the nominal interest rate and inflation rate in Colombia. Additionally, applies a cointegration test with regime change developed by Gregory y Hansen (1996), which allows present statistical evidence of the existence of a structural change in this relationship in the late nineties.