Retreating stop ultrasound needle guide systems are disclosed. In one example approach, a needle guide system includes a guiding component which can be positioned at different locations and angles on a mounting component, where the mounting component can be coupled to a distal end of an ultrasound probe. When positioned at the different locations and angles on the mounting component, the guiding component can guide a needle through the skin of a patient at a constant point and when the needle is advanced so that a hub of the needle reaches a stop of the guiding component, a tip of the needle is positioned directly underneath the ultrasound at a pre-selected depth.
