This study examined, in 180 children aged from 6 to 9?years, to what extent irregular word reading and spelling were predicted by vocabulary knowledge, reading frequency, orthographic processing and nonword reading skill. Consistent with models of reading highlighting the quasi-regular nature of irregular words, it was found that nonword reading was a large and significant predictor of irregular word reading even when entered into a regression analysis after all of the other variables. However, irregular word spelling was equally well predicted by orthographic and nonword reading skills. The results are discussed in relation to models of word reading and reading development.