Increasingly more educational centres are, therefore, carrying out programmes aimed at preventing or reducing violence in schools. This study seeks to examine the efficiency of such programmes in Primary and Secondary schools. The methodology used is the systematic search of electronic databases (Medline, Trip Database, Cochrane, Academy Search Premier, PsycINFO, ERIC and PsycARTICLES) for studies published after January 1, 2000, on the assessment of the effectiveness of school interventions to prevent or reduce violence and bullying. The study population comprises school-age (6-16 years) children and adolescents of both sexes. Initially, 299 articles were detected that met the inclusion criteria and that had been independently peer-reviewed. For the final evaluation, 32 studies were selected which met the previously established selection and quality criteria, and analysed by level of evidence. The review finds evidence of the efficiency of the programmes assessed, although serious limitations are also detected, which should be taken into consideration when designing future interventions. The likelihood of success is enhanced when all the disciplines of a centre are involved, and also the parents. It is also essential to adapt the diverse programmes to the social and cultural characteristics of the school population in which the programme is to be carried out. Finally, the findings indicate the need for continuity in the programmes if their long-term efficiency is to be guaranteed.