The recrystallization of hot-rolled aluminum strips was monitored inline after inline annealing at Commonwealth Aluminum Corporation (CAC) using laser-ultrasonics. The noncontact measurement is based on sensing the ratio of the compressional to the shear sound velocity in the strip thickness direction. This ratio is insensitive to strip thickness variations and varies with crystallographic texture and temperature. Therefore, recrystallization is sensed as a change of texture, from a rolling to an annealing texture. A pyrometer is used to decouple temperature and texture effects on the velocity ratio. The measurements were made on two alloys: AA5754 and AA5052. The capabilities and limitations of the sensor are discussed. Introduction: Aluminum sheets are often made by melting scrap aluminum, adjusting the chemistry, casting using a twin belt caster, hot rolling, cooling, batch annealing, and cold rolling. Clearly, letting the hot-rolled coil cool to subsequently anneal in a batch anneal furnace is less energy efficient than would be a new process involving hot rolling followed immediately by inline annealing. Moreover, energy savings and sheet quality would be optimal if the degree of recrystallization, a critical parameter in determining formability, could be sensed inline, following inline annealing. The inline annealing process (see Fig. 1) was demonstrated at the Commonwealth Aluminum Corporation (CAC) in Carson, California, together with a novel laserultrasonic sensor to monitor recrystallization. This paper reports on the ability of the laserultrasonic sensor to monitor recrystallization inline. Recrystallization measurement using laser-ultrasonic resonance spectroscopy: Previous work has shown that during recrystallization, the ultrasound velocity (longitudinal and transverse) varies monotonically from some initial, hotor cold-rolled value, to a final, annealed value. These velocity variations are essentially caused by changes in the crystallographic orientation distribution (also called texture) that occur during recrystallization. Generally, these initial and final velocities depend on temperature, alloy grade, and processing. However for a given industrial production line and alloy, a calibration can be obtained as a function of recrystallization state and temperature.