The invention relates to a tensioning device of a traction mechanism drive, having a tensioning lever (2) which is mounted on a base housing (4) so as to be rotatable by means of a pivot bearing (3) and, spaced apart radially from the rotational axis (5) of the pivot bearing (3), is provided with a rotatable tensioning roller (6), which tensioning lever (2) can, by means of a torsional spring (11) which is embodied as a coil spring (12), is arranged coaxially with respect to the pivot bearing (3) and is connected at both spring ends (13, 14) at the housing side to the base housing (4) and at the lever side to the tensioning lever (2), be acted on with a torsional moment MT about the rotational axis (5) of the pivot bearing (3), wherein the pivot bearing (3) comprises a bearing journal (7), a bearing hub (8) and at least one plain bearing sleeve (9) which is arranged between the bearing journal (7) and the bearing hub (8), and wherein a central radial force application plane (17) of the tensioning roller (6) is axially spaced apart from a central radial bearing plane (19) of the pivot bearing (3).