It starts on the A502 at traffic lights in Chalk Farm. Southbound B517 traffic can only access the eastbound A502 but all other movements are allowed.
The B517 then heads north along Ferdinand Street and Malden Crescent. It crosses the unclassified Prince Of Wales Road at traffic lights before continuing along Malden Road through Maitland Park. There is a short D1 section past St Dominic's Priory before the road crosses the Thameslink Line and ends at traffic lights on the B518. Owing to a one-way system on that road traffic heading west uses the road to the left whilst traffic from the west comes in straight ahead; the two sections combine along a two-way road to the right.