A low profile endocavity needle guide device for an ultrasonic probe is disclosed. The device includes a needle guide and a clamp assembly. The needle guide is a tubular member configured to enable an elongated needle to be extended through it. The clamp assembly includes a first clamp member, a second clamp member and a slidable member. The first clamp member is pivotable with respect to the second clamp member between an engagement position and a release position, and vice versa. The slidable member is mounted on the first clamp member and includes a low profile projection which engages a ramped surface of the first clamp member to pivot the first clamp member to the engagement position when the projection is slid up the ramped surface, and to enable the first clamp member to move to the release position when the projection is slid down the ramp surface.
