Individual differences in nonword repetition are associated with language and literacy development, but few studies have considered the extent to which learning to read influences phonological skills as indexed by nonword repetition performance. We explored this question using a latent variable longitudinal design. Reading, oral language and nonword repetition were assessed in 215 children at age 6 years and one year later at age 7. Reading at 6 years predicted growth in nonword repetition between 6 and 7 years, independent of the effects of oral language skills and the autoregressive effect of nonword repetition at 6 years, but nonword repetition was not a longitudinal predictor of the growth of reading. These findings demonstrate that learning to read has a powerful effect on children’s language processing systems. We consider how learning to read might influence speech processing, and discuss the implications of our findings for theoretical accounts of reading disorder.