The greater emphasis on the significance and difference in English performance between the school types has mainly been investigated across Asian countries. However, not much is known about what language skills differentiate their overall language achievement. Using a quantitative study with comparative analysis, this study measured the reading and listening skills of 1319 Indonesian students who were selected using a stratified sample design and grouped them into secular ("Sekolah," n = 726) and Islamic ("Madrasah," n = 593) groups. The samples were selected from 9205 of the total population of secondary school students, in Bone Regency, South Sulawesi Indonesia. The three-way ANOVA results showed a significant difference (p < 0.05) in reading and listening subskills between the groups. Highly significant results of "Madrasah" students in reading and listening subskills indicate they are better at constructing what text means in a variety of contexts, as a literary experience in reading texts and obtaining general and specific information from listening tests compared to those attending secular schools. Poor performance of boys and students who enrolled in public secular schools may become the main explanation for achievement gaps across the groups. The main and interaction effects of the school system, sectors, and gender on the tested subskills were also explained in this study. Additionally, the result of the DIF test confirmed that the equity of the tested items between them was supported.