An ultrasonic surgical instrument assembly includes a handpiece, a generator of ultrasonic mechanical vibrations disposed in the handpiece, a probe, and a light source. The probe is attached to a distal end of the handpiece and is operatively connected to the generator. The light source is removably attached to the handpiece and is configured and mounted to direct at least visible electromagnetic radiation in a direction along the probe so as to illuminate a surgical site distal of the probe.