A sensitive Rayleigh-scattering technique has been developed which combines the advantages of stimulated and classical scattering. Forward Rayleigh scattering (3-mrad angular separation) in NaF was observed between 300 and 20°K. The scattered intensity varies by more than 4 orders of magnitude within this temperature interval. Quantitative agreement with theoretical values based on the Landau-Placzek theory is found for T>80°K. Scattering rates considerably larger than expected are found for lower temperatures. © 1973 The American Physical Society.