The relationship between Romans 3:4 and Psalm 51:4 (Psalm 50:6 in the Septuagint) has long puzzled scholars. Many suggest that Paul's use of Ps 50:6LXX either seems not to fit the logic of Romans 3 or does not reflect the psalmist's meaning. This article offers an interpretation of Romans 3:4 that eliminates the apparent tension between the two texts. It clarifies Paul's meaning in Romans 3 by reinterpreting Psalm 51:4 in its context. Both Psalm 51:4 and Romans 3:4 refer to God's saving righteousness. The conclusion that Romans 3:4 speaks of God's saving righteousness is not unique to this study. However, typical arguments in favour of this view are susceptible to significant criticism. Specifically, they do not demonstrate how the whole of Psalm 50LXX shapes Paul's argument, and/or they do not explore the possibility that Psalm 50:6LXX also refers to God's saving righteousness. This article addresses both issues. After reviewing the theological and exegetical significance of Romans 3:4, four major questions that challenge readers today will be surveyed. Next, an integrated exegesis of both passages, showing how Psalm 50:6LXX sheds light on Romans 3, will be presented.