It starts on the A736 at the signalised Allan's Corner roundabout in Barrhead and heads north along Arthurlie Street. It crosses the Levern Water before going under the Glasgow to Kilmarnock railway line by Barrhead station.
The road then continues north along Paisley Road until it TOTSOs right on the edge of open country; the road ahead is the B774 which actually goes to the centre of Paisley but Paisley Road remains with the B771.
There is a short rural section on the B771 before it passes to the east of Dykebar Hospital and signs welcome drivers to Paisley. The road skirts the edge of the urban area before ending at a roundabout on the A726.