For applications in polymer electronics, suitable passivation coatings are searched for. Inorganic-organic hybrid polymers (ORMOCER®.s) have proven to be tunable in a wide range with respect to their physical properties. Their synthesis can be controlled such that the resulting materials show very low water vapor transition rates (WVTR) which is one of the most important key properties for passivation applications. Besides, ORMOCER®.s can be patterned by UV lithography due to their organic functional groups thus yielding the possibility of selectively passivate electronic circuits. Typical WVTR values which have been achieved so far for individual thin-film layers range between approximately 1 and 5 g/m2d (calculated for 100 μm layer thickness). The passivation properties will be discussed with respect to variations of the inorganic content and to the network formed upon processing.