The engineering of therapeutic and clinical candidate monoclonal antibodies and Fc fusion proteins is becoming more sophisticated at generating molecules that are better suited to the pharmacological activity required of them. There are at least 14 marketed and clinical candidate antibodies and Fc fusion proteins in which the Fc has been modified, either via changes in amino acid sequence or in glycoforms. Recent research and development activities in Fc engineering to generate 'fit-for-purpose' antibodies and Fc fusion proteins are reviewed.