This study investigated the effect of self-regulated learning, as indicated by academic self-concept, motivation and learning strategies, reading attitude and family based prerequisites on reading ability. Students (n=4018) in the eighth grade answered the IEA reading literacy test, the self-regulated learning questionnaire and a student questionnaire about their background. The exploratory factor analysis (EFA) revealed that the self-regulated learning questionnaire did not measure the intended three dimensions, but only two: Verbal/General academic self-concept and a new dimension called Goal oriented strategies. Structural Equation Modelling ("SEM") with a cross-validation sample was conducted to determine the effects in the final model. The strongest effect on reading ability was from Verbal/General academic self-concept (beta=0.43 for final and beta=0.56 for cross-validation model). Gender differences revealed that girls read better on narrative and expository texts, had a more positive reading attitude, and more positive verbal self-concept, whereas boys had a higher academic self-concept (not domain-specific), self-efficacy, control expectation, reported more memorising, elaboration, and instrumental motivation (all differences p less than 0.001).