This paper evaluates the consequences of overcrowding over violence in Argentinian prisons during 2002-2008. It is the first to analyze this problem for a Latin-American correctional system and additionally to address potential endogenity problems that originate from non-observable variables like the change in the effective level of supervision and in quality of life inside prisons. After solving the endogenity problems, results show that the rate of occupation has a positive effect over misconducts that lead to material damages and the probability of discover prohibited items. Nevertheless, no effect is found between overcrowding and violent conflict between inmates. The results are robust to different set of tests, however it is no possible to be certain if this last results emerges from the ability of prison administration to avoid that overcrowding lead to violent conflict between inmates or if it is due because violence conflicts has more sociological foundations, remaining this as a future topic of investigation.