The aim of this study was to extend the literature on tootling, an intervention consisting of student reports of peers’ prosocial behaviour. Effects on student on-task behaviour and disruptions, alongside teacher praise statements, in a New Zealand primary-school were investigated. A single-subject multiple baseline design, with a follow-up phase, was used in an evaluation of the effects of the intervention across three groups. Students were taught how to notice and record peers’ prosocial behaviour on slips of paper, which were collected each day before the teacher read several out loud to the class and provided feedback. An interdependent group contingency, whereby students worked together towards a shared goal, alongside public display of progress, was used to provide class-wide rewards for reaching a pre-determined tootle target. An increase in on-task behaviour across all three groups, decreases in student disruptions of one group, and little, to no change in teacher praise statements were found. Results mostly remained consistent during follow-up observations. Teachers and students rated the intervention socially acceptable and, according to treatment integrity scores, tootling can be used effectively in a classroom setting. Implications and future directions are discussed.