The main aim of this study was to find out what kind of factor model of written language skills could be created on the basis of tests of reading accuracy and fluency, spelling and reading comprehension, and how the written language skills factor and school achievement predict choice of secondary education and what effects gender, special education support and socio-economic background have on this prediction. Altogether 1700 students were assessed with two word-level reading tests and word- and pseudo-word-spelling tests and by a reading comprehension test. Remaining data were elicited with a questionnaire. The findings showed that a latent written language skills factor could be formed, separately for boys and girls, and that the level of difficulties in reading and spelling predicted powerfully school achievement and choice of secondary education. The effect of reading and spelling skills on secondary education choice was much stronger and direct for boys. Parents' occupation and special education support did not play a major role as predictors.