A noninvasive laser ultrasonic method has been used to investigate the melting and solidification of a (Cd,Zn)Te alloy during vertical Bridgman growth. A single zone vertical Bridgman furnace was integrated with a laser ultrasonic system and used to monitor the time-of-flight of ultrasonic pulses that propagate across an ampoule during the melting and solidification of Cd0.96Zn0.04Te. The measurement approach is based upon the difference in the elastic stiffness of the solid and liquid phases of Cd0.96Zn0.04Te (Queheillalt et al., J. Appl. Phys. 83 (1998) 4124) and its significant dependence upon temperature. This results in a reduction of the longitudinal wave ultrasonic velocity as the temperature was increased (from ambient temperature) followed by a similar to 45% decrease upon melting. The laser ultrasonic sensor provided a robust in-situ method for monitoring the melting and solidification of Cd0.96Zn0.04Te. The data indicated that the melting was slow and that solidification was accompanied by a 10-15 degreesC undercooling.