There is a long tradition of theoretical and empirical research linking intelligence to criminal activity. At the same time, the extant literature has been slow to examine this relationship in other settings. One such setting in which this relationship may also manifest is the prison environment, where knowledge on the determinants of prison misconduct has important implications for prison management and security. Drawing from a representative sample of inmates from a large Southern state in the US, the current study presents the first assessment of the relationship between intelligence and prison misconduct. The effect of intelligence, measured via the WAIS-R, on violent prison misconduct is analyzed controlling for inmate and prison-level factors. Results indicated that the individual's IQ, as well as the average IQ of the prison unit, was significantly and negatively related to violent prison misconduct. Implications and directions for future research are highlighted.