Classical music has been pumped into the Edwardian Prince's Tunnel, linking Dartford's Central Park with Brooklands Lakes, for the past four years.
Jeremy Kite, leader of Conservative-controlled Dartford Borough Council, said initially the music was played to uplift people using the tunnel.
But he said it was soon apparent that any vandals were leaving it alone.
He said: "We weren't getting any of the anticipated graffiti and none of the damage you'd normally expect in an urban tunnel.
"The only difference between this subway and other subways in the town is the fact that we're playing classical music."
The music has been played in the tunnel since it was renovated for the benefit of the town's residents and visitors after falling into disuse.
Mr Kite said the installation of the music and the lighting system in the tunnel cost just less than Â£20,000, and was "money very well spent".
"The impact has been enormous," he added.
Music played in a pedestrian tunnel has stopped any graffiti or anti-social behaviour, according to a Kent council.