Spectroscopic properties of metal complexes of thiourea single crystals (tris thiourea zinc acetate, bis thiourea cadmium zinc acetate and bis thiourea ammonium chloride) which are non-linear optic materials were investigated by Raman scattering spectroscopy. The vibrational frequencies of the functional groups are identified and assigned. Effects due to the coordination of thiourea with metal ions are analyzed. Hydrogen bonding interactions involved in the metal complexes are observed in the Raman spectra.