Polymeric materials bearing polar groups constitute a class of macromolecules with interest in a number of uses. Because the direct synthesis employing polymerization strategies from polar monomers is very often precluded by catalyst poisoning or uncontrolled side reactions, the alternative postpolymerization route consisting in modifying a previously prepared polymer is continuously progressing. However, such a posteriori modification depends on the existence of potential reaction sites in the polymer. Because of this, polyolefins are the most challenging substrates to work with and, among them, the saturated ones. In this contribution, the current state of the art of the metal-catalyzed modification of polyolefins and subsequent polar group incorporation is provided.