While the effect of Readers Theater (RT) on English oral reading fluency has been extensively investigated, research on the effect of RT on adolescents' English reading and listening comprehension was scant and yielded different results. This research aimed to explore how RT instruction influenced English as a Foreign Language (EFL) students, especially adolescents, in English reading and listening comprehension. This article conducted a 10-week quasi-experimental design involving two intact classes of 68 seventh-grade students from central Taiwan. The instruments included pretests and posttests of English reading and listening comprehension and nine students were interviewed for an in-depth analysis. The results revealed that the experimental group statistically significantly outperformed the control group on reading comprehension, but not on listening comprehension. Consequently, despite the advantages of RT instruction on reading comprehension stated in the article, interaction among learners in terms of listening comprehension is needed to be emphasized in the course when adopting the RT instruction.