Techniques for preventing parasitic beamlets from affecting ion implantation are disclosed. In one particular exemplary embodiment, the techniques may be realized as an apparatus for preventing parasitic beamlets from affecting ion implantation. The apparatus may comprise a controller that is configured to scan a spot beam back and forth, thereby forming an ion beam spanning a predetermined width. The apparatus may also comprise an aperture mechanism that, if kept stationary, allows the spot beam to pass through. The apparatus may further comprise a synchronization mechanism, coupled to the controller and the aperture mechanism, that is configured to cause the aperture mechanism to move in synchronization with the scanned spot beam, allowing the scanned spot beam to pass through but blocking one or more parasitic beamlets associated with the spot beam.