This study deals with empirical collection and analysis regarding terrorist attacks in Portugal, Ireland, Italy, Greece and Spain during the Economic crisis and the effects of the economic crisis on certain types of terrorist groups. The aim of the study is to contribute empirically to the “root causes” debate within Terrorism studies. It also contributes by making certain adjustments to existing categorisation of terrorist groups. The research methods used are both quantitative and qualitative and the research strategy is of a hypothetical-deductive nature. Findings conclude that the Puritanical Anarchist type of terrorism has seen an increase during the crisis, but only the Social Revolutionary type shows a propensity for using the crisis as a reason behind attacks. The study contributes to the barren empirical and theoretical landscape within Root causes.