The self-centering feeding device (20') for elongated objects such as logs includes a conveyor means (30) carried by a parallel mechanism having a vertical stationary part. The parallel mechanism is connected to a mechanical engagement means (26) and is controlled by a driving means (28) activated when an object on the conveyor means reaches a predetermined position, and is then kept activated the whole time during which the object is fed-through. The object is thus firmly clamped between the conveyor means and the engagement means and has no possibility to rotate about its longitudinal axis. The conveyor means may therefore be much shorter than the object. The invention is suitable for general application, but in particular for application in the log processing industry.