The first formal instruction of reading typically takes place in the school environment setting. Therefore, there is good reason to predict that children’s classroom behaviours at the time of formal learning will influence their early reading acquisition. The present study compared the extent to which symptoms of hyperactivity/inattention, conduct problems, emotional problems, peer relationship problems and pro-social behaviour predicted children’s pre-reading (letter-sound knowledge, phonological awareness) and word reading development. Seventy three new school entrants were assessed during their first 2 years at school. Children were assessed at T1 (prior to reading instruction) on pre-reading and word reading, at T2 (approximately 6months later) on pre-reading, word reading and classroom behaviours and at T3 (1 year after T2) on classroom behaviours and word reading. Overall, hyperactivity/inattention was the strongest predictor of pre-reading and word reading development, but not the only predictor. Implications for education are discussed.