In a communicative approach to language teaching, students are presented with “authentic” language, which is thought to allow them to produce it in a nativelike way. The current study explores whether the lexical bundles in communicative Japanese junior high school textbooks are representative of conversational English. To do this, the study uses a corpus-based approach that compares the most frequent lexical bundles in the textbooks to those in an English reference corpus. The study finds that although lexical bundles are very frequent in the textbooks, and conform relatively well to English patterns at shorter lengths (3-word lexical bundles), they deviate considerably at longer ones (4-, 5- and 6-words). This has important implications for the communicative utility of the language in the textbooks.