An examination has been made of the general design principles of gel-immobilized metal-complex catalytic systems (GICSs). The main properties of GICSs are compared with those of traditional heterogeneous, homogeneous and heterogenized metal-complex catalysts. The advantages of GICSs are demonstrated for the case of the dimerization of lower olefins, and the prospects of their use in different liquid-phase petrochemical processes are indicated.