Harassment among peers is a reality framed in higher education. In addition, new technologies can be a vehicle for the appearance and propagation of the phenomenon. The main objective in this research was to analyse the validity and reliability of the Questionnaire on Harassment among University Students (QAEU in Spanish), a tool designed for its detection. It is a psychometric tool composed by three scales: object, agent and bystander. There were 765 students of Degree and Master from a university of the Spanish southeast with an average age of 23.27 (SD = .81), with 72.7% women. The results showed a reliability by Cronbach' Alpha of .970. The structural equations model, analyses for confirming the constructs of the questionnaire (forms of aggression, ways and moment of aggression), presented robust model for victim scale, aggressor scale and even for bystanders scale. In conclusion, the QAEU is a tool with a high internal consistency and is valid for being used in research, practical situations and innovation areas.