This paper studies the influence of regional inequality within countries on internal conflicts. Regional inequalities are measured by the population-weighted coefficient of variation of regional GDP per capita. As the main innovation, I use a panel dataset of country-level regional inequalities, which covers 56 countries (835 subnational regions) between 1980 and 2009. I also consider a broader cross section dataset for the year 2005, which covers 110 countries (1569 subnational regions). Conflict is measured by the incidence of civil war (UCDP/PRIO data) and a risk measure of internal conflict (war, terrorism and riots) provided by the PRS Group's International Country Risk Guide. Logit estimations are employed as well as OLS fixed effects panel regressions. I find that regional inequalities increase the risk of internal conflict.