The invention relates to an engine suspension pylon for an aircraft including a rigid structure provided with a box (24), this pylon also including an engine aft attachment (8) provided with an attachment body (38), and a thrust resistance device (9) generated by the engine. The rigid structure according to the invention includes an offset rib (35) for the attachment body (38), this rib (35) being mounted fixed on the box (24) between the box and the engine (2) and carrying the attachment body. Furthermore, the device (9) includes a thrust resistance spar (9b) of which the forward end is mounted fixed on the rib (35), and the aft end is mounted fixed on the box.