This study investigates the causal relationship between terrorist violence during the Years of Lead and the decline in voter turnout in Italian political elections. The analysis, which covers electoral participation at the NUTS-3 level from 1972 to 1992, relies on data from the Global Terrorism Dataset for information regarding domestic terrorist attacks. Using causal mediation analysis (CMA) and the front-door criterion (FDC), we identify how the magnitude of attacks – measured by casualties, injuries, and material damages – affects electoral participation. Our findings reveal a nuanced impact of terrorism. Specifically, the results are mainly driven by material damage and to a lesser extent by the number of casualties.