The metallization of glass surfaces modified by various methods was investigated. For applications in the electroplating industry the metal layer has to reach a thickness of 30 mu m, and adhesion to the underlying glass is poor at this thickness. Previous investigations using polymers as dielectrics showed a good correlation between the surface tension of treated polymers and adhesion. Therefore, the glass surfaces were modified using organosilanes and reactive plasma and the modified surfaces were investigated using scanning electron microscopy and surface tension measurements. Though the critical surface tension of the silylated surfaces in some cases matched the critical surface tension of the metal (copper or nickel) well, no improvement in adhesion could be attained. The plasma-treated glasses showed inhomogeneities in surface topography and therefore surface tension. The scatter in the surface tension values was high, and the plasma treatment was not very reproducible. The results showed that neither of the two treatments could be used successfully for building a metal-glass composite.