Objective. Learn about the implicit theories used by parents who are victims of their children’s violence to explain their start. Method. A qualitative exploratory study has been carried out in accordance with the method proposed by the reasoned theory. The information was obtained from six discussion groups guided by semi-structured interviews and analysed by ATLAS.ti 5.0. In total, 42 parents who were victims of parental violence participated (VFP; 18 fathers and 24 mothers) selected by theoretical intentional sampling from two contexts: a youth reform centre and a private centre specialising in intrafamiliar violence therapy. Results. Parents maintain three theories to explain the start of VFP: (a) the theory of the missing pupil, which refers to school absenteeism as a predictor of violent behaviour; (b) the theory of the consumer pupil, where the use of substances (alcohol, cannabis and cocaine) would be the precursor; and (c) the theory of accumulation of tension, which raises the existence of previous factors that would contribute to increasing unrest (‘rabies’) preceding drug abuse and subsequently violence towards parents. Conclusion. The parents point out that VFP coincides with the start of secondary education. One aspect common to the three emerging theories is that the main triggers for VFP are distant factors and related to the environment surrounding adolescents, leaving aside variables related to family dynamics.