A furling and adjustment assembly for boat sails, includes a hooking device, configured to be mated to a coupling for the sail and to a tack sheet. The assembly also includes an actuation pulley assembly, configured to be actuated by an actuation rope and functionally associated with the hooking device in order to transmit, by way of the latter, a furling/unfurling movement to the sail. The hooking device and the actuation pulley assembly can be mutually moved between a condition of mutual engagement and a condition of mutual disengagement, so as to allow the adjustment of the tack point of the sail while a fixed spatial position of the actuation pulley assembly remains constant.