Polydimethylsiloxane (PDMS) is a hybrid inorganic-organic polymer with unusual combination of physical and chemical properties, such as extremely low Tg(−123 °C), excellent low temperature flexibility, good thermal and oxidative stability, low electrical and thermal conductivity, high gas permeability, surface activity, and biocompatibility. One major drawback of PDMS polymers is their very poor mechanical strength, which makes them unsuitable for structural applications unless they are highly filled and covalently crosslinked. This can be overcome by the preparation of PDMS containing segmented or block copolymers with various other organic polymers. In this article, synthesis of reactive functionally terminated PDMS oligomers and their utilization for the preparation of various segmented silicone copolymers are discussed. Emphasis will be given to elastomeric silicone-urea copolymers, their preparation, characterization, and elastomeric behavior.