The relationships are explored between language and literacy and academic success at 16 years in an English sample of 62 young people with a history of specific language impairment identified at 8 years. Data were available from national assessments at 16 and 14; in addition the pupils had completed a range of standardized tests to examine language, literacy and non-verbal ability at 10 years and 8 months and at 16 years. Concurrent measures of literacy had the highest correlations with academic performance. However, analysis revealed a complex model identifying relationships between academic performance at 16 and previous academic attainments in secondary school (national assessments at 14) and a measure of language (listening to paragraphs, Clinical Evaluation of Language Fundamentals 3 or CELF-R[superscript UK]; Peers et al., 1999). Standardized measures of literacy, non-verbal ability and listening to paragraphs (CELF-R[superscript UK]) taken at age 11 accounted for over 50% of the variance in performance on Key Stage 3 (KS3) assessments at 14 in English, maths and science. Current gaps in our understanding of the factors that support successful school performance are discussed. (Contains 5 tables, 2 figures, and 1 note.)