The purpose of this paper of this paper is to explore the immigration and productivity in Spain. We estimate the effect of immigration on labor productivity from 2004 until 2008 for Spain. Using firms (SABI) and individuals data (Social Security Records) we calculate the effect by sector and municipality for the two big Spanish provinces that have received most immigrants in the last decade: Barcelona and Madrid. After controlling for endogeneity of immigration, the results demonstrate that immigration have a negative effect on productivity. Education and occupation are both variables with a positive effect on productivity, while permanent, public or full time contracts do not have any effect. Type of immigration, Europeans 15 (more skill) versus no European, is not relevant in explain the negative productivity. This fact is due that firms are very heterogenous across them and use their employees under their real production potential.