**Faculty of Education, Ekiti State University, P. M. B. 5363, Ado-Ekiti (NIGERIA) *Institute of Education, Faculty of Education, Ekiti State University, P. M. B. 5363, Ado-Ekiti (NIGERIA) ***Ondo State University of Science and Technology, P. M. B. 353, Okitipupa, Ondo State (NIGERIA)

This study investigated the applicability of Flesch’s formula in assessing the readability of Basic Science textbooks in selected Junior Secondary Schools in Ekiti State, Nigeria. The study employed an applied research technique and generated data from the pages of each textbook used. The sample consisted of all the Basic Science textbooks used in Ekiti State Junior Secondary Schools. The data collected were analyzed using average sentence length, average syllable count, grade levels and the reading age of the books. The results revealed that STAN Basic Science Book 3 published by Science Teachers Association of Nigeria, Longman Basic Science Book 1 published by Longman Publishers (Nig) Plc, and Evans Basic Science Book 3 published by Evans Brothers (Nig) Ltd. were fairly difficult for the readers with readability grades higher than the target readers. The results also showed that the books contained long sentence length and polysyllabic words that needs to be re-visited. It is therefore recommended that long sentences and polysyllabic words of the books should be split into simpler components for easy comprehension.