The present study examines the extent to which adolescents' reading affect (reading motivation) and behaviour (reading habits) predict different components of reading (word reading, comprehension, summarisation and text reading speed) and also adds to the limited research examining group differences (gender, age, ability) in adolescents' reading motivation and reading habits. A representative sample of three hundred and twelve students (aged 11-16) from the UK participated. Adolescents' reading motivation predicted significant variance in their reading comprehension and summarisation skills, after accounting for word reading and text reading speed. Reading motivation also predicted significant variance in text reading speed after accounting for word reading. Notably, however, different dimensions of motivation predicted variance in different reading skills. Of all the reading habits, only fiction book reading emerged as a consistent predictor of variation in the different reading skills, after accounting for the other reading abilities. Group differences (gender, age and ability) were consistent with previous literature.