With a rich, productive career spanning over 60 years, culminating in the award of the Nobel Prize for Literature in 1988, Naguib Mahfouz's literary works have naturally attracted numerous studies and critiques. These studies have covered a great many aspects of Mahfouz's creative writing, but, perhaps because of the secular, modern education Mahfouz received (both at school and in the Department of Philosophy in Cairo University), and his personal lifestyle, they have concentrated on the socialist, materialist, and structural aspects of his work. Perhaps because of this, one important aspect of his writing has largely escaped attention: his artistic use of the language of the Qur'an. Mahfouz does not signal that a given phrase or reference is Qur'anic, leaving it to blend with the text, and making it easy to miss the fact that the Qur'an played any part in Mahfouz's use of language. However, to a reader who knows the Qur'an by heart the presence of Qur'anic language in his works is obvious, and equally obvious is Mahfouz's artistic talent in using it. Eventually, he himself announced at the end of his life that he had always had an intimate interest in the Qur'an, read it daily, and benefited from it. This article seeks to demonstrate the ubiquitous presence of Qur'anic language in Mahfouz's works, and the skill and subtlety with which he used it.