A home-based reinforcement (H-BR) programme was carried out in a secondary school to increase rule-following and work completed by two groups of disruptive students. Of particular interest was whether the positive effects of the programme on target students would ‘spill-over’ to equally disruptive control students in the same classes. The results showed highly significant improvements in the work and behaviour of both sets of target students but positive ‘spill-over’ effects on controls were only apparent in one of the classes. Possible explanations for this are discussed. It is concluded that the already considerable value of H-BR programmes in secondary schools as minimal intervention techniques would be enhanced even more if ‘spill-over’ effects on non-targeted, classroom sub-groups could be planned for, rather than hoped for.