Pre-print, Working paper: This paper contributes to the heated debate on the link between climate and civil war. We exploit a large dataset of a drought index commonly used in hydrology, the Palmer Drought Severity Index (PDSI). The PDSI is based on a hydrological model and is a cumulative measure that takes account of past climatic variables. Our analysis takes account of country fixed effects, removal of the most influential observations, use of alternative sample periods and changes to the battle-death threshold. Overall, results show a robust link between drought and civil war in Sub-Saharan African states after independence.