Marcion's Gospel of the Lord was a text used by the mid- 2nd-century Christian teacher to the exclusion of the other gospels, and now its reconstructed fragments appear among the New Testament apocrypha. So many Catholic apologists wrote treatises against Marcion after his death, in addition to the famous diatribe by Tertullian, that it has been possible to reconstruct almost the whole of Marcion's Gospel of the Lord from their quotations.

The gospel appears to have been based on the Gospel of Luke but missing out the first two chapters concerning the nativity and beginning at Capernaum, and with modifications of the remainder suitable to gnosticism.

A controversial suggestion by recent scholars is that Marcion's gospel is actually based on an earlier version of Luke and more accurately reflects it than the canonical gospel. Marcion made the same claim, although the church, who also were biased in the matter, disputed this.