We investigate the effects of age-related factors and formal instruction on the development of reading-related skills in children aged 4 and 7 years. Age effects were determined by comparing two groups of children at the onset of formal schooling; one aged 7 (later-schooled) and one aged 4 (earlier-schooled). Schooling effects were measured by comparing the later-schooled group with earlier-schooled age-matched controls. There were significant effects of age and schooling on phonological awareness and visual-verbal learning, and an effect of age, but not schooling, on vocabulary and short-term verbal memory. We conclude that age-related factors and reading instruction contribute to the development of phoneme awareness and that vocabulary and verbal memory improve with age. (Contains 4 tables and 2 footnotes.)