Laser-Ultrasonics (LUS) provides a means of obtaining microstructure information continuously and non-destructively both in the laboratory and for quality control on-line in industry. Ultrasound is both generated and recorded using lasers which permits remote, non-contact operation with fast sampling and also the capability of working at high temperatures or at moving surfaces, for example during industrial continuous annealing. Examples of dynamic heating trials will be presented for samples of cold rolled steel sheets where primary recrystallisation and ferrite-austenite transformation are monitored in-situ as a function of temperature. Examples are also presented where the grain size of low carbon steels have been quantitatively analysed and show very good agreement with microscopy methods.