The study reported in this article investigated task-repetition with young Japanese children. Fifteen children with no prior knowledge of English completed a communicative listening task that was designed to introduce new vocabulary. The same task was repeated nine times over five weeks. In line with Allwright's (1984) claim that "interaction is the fundamental fact of language pedagogy", the interactions that arose during the repeated performance of the task were analysed both quantitatively and qualitatively to examine (1) the input provided by the teacher, (2) the learners' voluntary production, (3) the learners' comprehension, (4) language learning and (5) the learners' motivation to communicate in English. The study found that repeating the same task resulted in changes in the teacher's input and students' output. The learners' comprehension improved steadily and their motivation to engage actively in the task remained strong throughout. The article concludes by discussing a number of general principles that can guide teachers when repeating the same task with young learners. (Contains 5 tables and 2 figures.)