This study examines the effects of children’s ability of word decoding in second grade on academic success in ninth grade. It is believed that children with a high level of word decoding in second grade have advantages throughout the educational system compared to children with a low level of word decoding. The aim of the study is to investigate the predictive power of early word decoding on later academic success in comparison with non-verbal cognitive ability. A Swedish cohort of 2165 children in second grade (8 year) was investigated with two tests of word decoding (the Word chains test and OS 400) and a non-verbal cognitive ability test (Raven’s matrices). Academic success was defined as marks in school subjects and educational choices, collected from the children’s’ school leaving certificates (16 year). As expected, preliminary results show that word decoding have a moderate correlation with marks in school subjects and is a much better predictor of success than non-verbal cognitive ability. Additional results will be discussed.