ABSTRACT Purpose The study presents the process of developing of an instrument for collective evaluation of reading fluency and comprehension of secondary elementary school students in grades 6-9 and verifies the effect of schooling on performance in the instrument. Methods 100 students regularly enrolled in grades 6-9 in secondary elementary public schools participated in the study. The construction of the instrument involved seven steps, with the participation of two judges. The instrument was composed of narrative text appropriate for secondary elementary school students and for 10 multiple choice questions, which five were literal questions and five were inferential questions. Results The results showed a better performance for the participants with higher schooling in fluency and in reading comprehension. The reading fluency presented positive and moderate correlations with the reading comprehension. Conclusion The instrument is easy to apply and analyze, and can be used in clinical, educational and research context to measure the performance of students in grades 6-9 in fluency and reading comprehension.