Purpose - An investigation of parallels between homegrown, international, and domestic terrorism. Methodology/approach - A comparative method is used to analyze data from two main sources, ITERATE data on international and the TWEED data on domestic terrorism. The similarities are tested in various dimensions - target types, severity, and the method of the attacks. Findings - Homegrown terrorism is inherently motivated by domestic issues. Moreover, variables of ethnic heterogeneity, political inclusiveness of fringe groups, and problems in the democratization process are good predictors of the occurrence of other forms of domestic and homegrown terrorism alike. Research limitations/implications - Number of observable cases of homegrown terrorism are low. The two main datasets have potentially overlapping incidents. Originality/value - Provides and operational definition of homegrown terrorism and test empirically the similarity between homegrown and other types of terrorisms.