When a child does not seem to be ready for primary school, a popular practice is to grant the child more time by letting it repeat kindergarten. However, previous quasi-experimental research demonstrated negative, though diminishing, effects of kindergarten retention on academic learning during the first years of primary school. The present study extends the existing evidence by addressing children's post-treatment school trajectories. Analysing data from a large-scale longitudinal study, we find that, on average, kindergarten repeaters would perform better for mathematics until five years later, were they promoted to first grade instead. However, if promoted instead, kindergarten repeaters would also have a higher likelihood to be retained in first grade and, under that condition, have a lower growth rate and score lower for mathematics five years later.