Objective This quasi-experimental study reported the results of a structured literacy intervention programme designed for secondary school students of Year 7 to Year 9 with dyslexia. Students of the intervention group (n = 116) participated in 40-week sessions of small-size, classroom-based, and split-group intervention setting with 45-min daily lesson on both Chinese and English language compared with students in the control group who received normal classroom instructions (n = 98). Results Students in the intervention group outperformed the control groups in self-regulated learning scales, which indicated that there was positive change in students' behavioural and cognitive outcomes in learning. Although students demonstrated gains in phonetic skills, posttest results in academic achievement did not exhibit significant improvement when compared with their control group peers. Conclusion The findings provided some encouraging evidence of the effectiveness of intervention programme. Students that demonstrated gains in phonetic skills and improvement in behavioural and cognitive aspects required continuous intervention lessons to become a self-regulated learner, who would be self-motivated to improve methods of learning and adopt strategies for attaining academic goals. The study contributed to the literature by presenting one of the very first school-based, small-size, classroom-based, and split-group intervention programme for secondary school dyslexic students, which included teachers and students training on English and Chinese intervention content (phonological and literacy content), teaching curriculum integrated with school curriculum, and coteaching with school teachers in the mainstream classrooms, whereas most of the existing intervention programmes used pull-out approach involving the first language only. [Copyright of Dyslexia is the property of John Wiley & Sons, Ltd.]