Few Taiwanese child abuse studies have focused on the impact of witnessing domestic violence on self-harm. Therefore this study aims to understand the effect of witnessing domestic violence and child abuse on adolescent self-harm in Taiwan. Using stratified-cluster random sampling, the subjects consisted of 1,033 students from six metropolitan junior high schools in Taiwan. The collected data was analyzed using the nested regression model. Major findings were: self-harm was positively related to witnessing parental verbal violence and exposure to parental abuse; however, self-injury was not associated with witnessing severe marital violence, experiencing physical punishment or serious family violence. Based on these findings, suggestions are made for practice and future studies.