A system and method are disclosed for planning a percutaneous procedure and for guiding an instrument to engage a target within a patient's body. A patient 3-dimensional image data set is provided, within which a user selects a skin entry point and a target point. A line, or “planned path,” is generated between the points which is used to align a movable arm to achieve a “Bull's Eye View,” in which the two points are superimposed. The instrument is placed at the skin entry point and aligned using the Bull's Eye View along a desired trajectory that intersects the target. Initial alignment is verified using fluoroscopy. Progression fluoroscopic views are used during the insertion procedure to ensure the instrument remains on the planned path. When the instrument reaches the target, a procedure may be performed, such as a biopsy, a drainage procedure, a radiofrequency ablation, or other medical interventional procedure.