This article examines how and to what extent unions affect companies' innovation in Chile. It contributes to the existing literature in the following two aspects: First, because it widens the scope of analysis focusing in a developing country that is characterized by some specificities regarding the innovation as well the union landscape. Second, because it provides more in-depth analysis, taking into account the effect of unions on the four different types of innovation proposed in the Oslo Manual by OECD. Results show that unions do not affect product and process innovation while influence organizational innovation and marketing in a non-linear way.