BACKGROUND: Developmental reading problems show strong persistence across the school years; less is known about poor readers' later progress in literacy skills. METHOD: Poor (n = 42) and normally developing readers (n = 86) tested in adolescence (ages 14/15 years) in the Isle of Wight epidemiological studies were re-contacted at mid-life (ages 44/45 years). Participants completed a spelling test, and reported on educational qualifications, perceived adult spelling competence, and problems in day-to-day literacy tasks. RESULTS: Individual differences in spelling were highly persistent across this 30-year follow-up, with correlations between spelling at ages 14 and 44 years of r = .91 (p