This study of English as a second language (ESL) reading textbooks investigates cohesion in reading passages from 27 textbooks. The guiding research questions were whether and how cohesion differs across textbooks written for beginning, intermediate, and advanced second language readers. Using a computational tool called Coh-Metrix, textual features were compared across the three levels using Multivariate Analysis of Variance (MANOVA). The results indicated that some features of cohesion yielded significant variation, but with small effect sizes. The majority of cohesion features considered were not different across the textbook levels. Larger effect sizes were found with factors like length, readability and lexical or syntactic complexity.