The B6398 is a short road in north Roxburghshire. Except for the eastern end, which is part of the pre-bypass A68, the road was originally unclassified; it had gained its number by 1932.
The road starts at a junction with the B6359 immediately west of Bowden and heads east through the village centre before continuing on and descending into Newtown St Boswells. Here we go round two sides of the Scottish Borders Council offices to reach a T-junction.
Originally the B6398 ended here on the A68; that road now bypasses the town and so we TOTSO right (left is the B6340) to double back on ourselves. We go through the village centre to end at a T-junction on the present A68 at the southern end of the Newtown St Boswells bypass.