A device for feeding tree trunks comprises a body structure (1) and support members (2) arranged on the body structure and supporting members (3) for feeding a tree trunk located between the feed members. The support members with associated feed members are moveable towards and away from each other by means of power members (4) to adjust the distance between the feed members located on either side of the tree trunk to the coarseness of the trunk. The device comprises members (5), which by abutment against the trunk locate the same so that longitudinal center lines of the trunk will obtain different positions generally transversely to the direction (R) of the relative mobility of the feed members towards and away from each other in dependence of the trunk coarseness. The device comprises means (24, 25) for displacing the feed members (3) supported by the support members (2) relative to the body structure (1) to maintain the feed members (3) in a position generally opposite to the trunk independently of the varying location of the longitudinal center line of the trunk occurring due to coarseness variation.