A crossbow with an improved cocking assembly. The improvement includes a means for automatically disengaging a hook associated with a cocking assembly from a bowstring once the bowstring has been drawn the desired distance behind a bowstring retainer. The automatic disengagement of the hook from the bowstring reduces movement and sound associated with disengagement, and reduces the likelihood of injury associated with placement of the fingers in front of the cocked bowstring. The disengagement mechanism may either be mechanical or magnetic as desired.