A circular knitting machine for hosiery or the like, comprising a needle cylinder with vertical axis and multiple axial surface slots, each of which accommodates a needle and an actuation element for the needle. The actuation element comprises at least one connecting element. The connecting element is provided with a radially extractable movable heel, that engages connecting element actuation cams facing the lateral surface of the needle cylinder. The cams comprise at least one extraction cam or one retraction cam, which has a portion whose profile is inclined with respect to an ideal plane perpendicular to the axis of the needle cylinder. The machine comprises extraction means causing extraction of the movable heel and keeping thereof in extracted position over the entire extension of the portion having an inclined profile of the extraction cam or of the retraction cam.