This study examined the effects of Collaborative Strategic Reading (CSR) instruction on the reading comprehension of Thai university students majoring in Electrical Power Engineering. The participants were 15 more proficient and 15 less proficient learners studying in an English for Academic Purposes (EAP) course. The scores from the pre-and postreading comprehension tests were compared after 10 weeks of CSR instruction. The results from the Paired-sample t-test indicated that both proficiency groups significantly improved their reading comprehension. With regard to the six reading skills investigated, the results showed significant improvement in the main idea, referential relationship, vocabulary in context, and inference skills, but not in the factual information and organization and logic skills. To explore the participants' perceptions towards the intervention, an attitude questionnaire and a semi-structured interview were used to collect data. The responses revealed positive perceptions towards the use of CSR instruction. Therefore, it can be concluded that the combination of strategy instruction and cooperative learning in CSR helps improve EAP learners' reading comprehension and enhance their active involvement in cooperative learning groups. It is suggested that EAP teachers use this viable multicomponent instruction to help improve learners' reading comprehension and active class participation.