A tensioning device (11) for a traction mechanism drive (1) which is arranged on an internal combustion engine and includes a drive wheel (3) arranged on a drive shaft (30) of an engine (4), one or more additional driving wheels (5, 6), and a continuously revolving traction element (2), which wraps around the drive wheel and additional driving wheels. The tensioning device has two tensioning arms (13, 14) having tensioning wheels (9, 10) mounted thereon, which apply a tensioning force to the traction element in front of and behind the drive wheel in the direction of revolution, and is provided with a spring (16) generating the tensioning force, and a tensioner housing (12), which movably mounts at least one of the tensioning arms to which the force of the spring means is applied. The tensioner housing is mounted on the engine pivotably about the axis (29) of the drive shaft.