A metastable crystalline state is reported to occur in amorphous SiGe films on oxidized Si under illumination with cw visible laser. This state is reached for laser power below the threshold for irreversible crystallization. The observation of this state is performed by Raman spectroscopy. It is found to be reversible and temperature- and composition-dependent. The main properties of this metastable state are described in terms of the Raman spectral features.