Grievance and reduced opportunity costs are two popular ideas within the civil war literature to explain participation in violent rebellion. We test both hypotheses at the village-level using data on recruitment activities during the civil war in Burundi. We use historical data on violent attacks in 1972 and 1988 as a proxy for grievance. The cross-sectional analyses report no effect of grievance on the likelihood of recruitment. By contrast, they do show tentative support for the idea that reduced opportunity costs may promote recruitment. Villages that had above mean incidents of ‘insufficient rain’ were more likely to have recruitment activities than others. We find similar results when we use recall information on recruitment to construct a 13-year panel. Negative income shocks through adverse weather conditions are a strong predictor of recruitment. By contrast we find no effect of commodity price shocks. These findings are consistent with a recent conclusion from literature: commodity price shocks show no robust relationship with civil war violence while weather shocks do.