What type of Old Testament text did Matthew use as editor of his Gospel? On the one hand, the editorially inserted fulfilment quotations with their peculiar textual form may be expected to represent Matthew's biblical text. On the other hand, the remaining OT quotations are mainly Septuagintal, and it is often assumed that Matthew reinforced the Septuagintal character of the quotations which he found in his sources. In the first part of this study, the fulfilment quotations are examined. Their textual form is best explained as a Septuagint text that was revised to make it better agree with the Hebrew and to improve the quality of its Greek; the evangelist took these quotations from a continuous text. In the second part, Matthew's remaining OT quotations are investigated. If Matthew borrows quotations from his sources, he does not adjust them to the LXX but he simply copies them or edits them in his usual way; if he inserts quotations into his sources, he makes use of his revised Septuagint. On the whole, this revised Septuagint seems to have been "Matthew's Bible".