Maximizing the expression yields of recombinant whole antibodies and antibody fragments such as Fabs, single-chain Fvs and single-domain antibodies is highly desirable since it leads to lower production costs. Various eukaryotic and prokaryotic expression systems have been exploited to accommodate antibody expression but Escherichia coli systems have enjoyed popularity, in particular with respect to antibody fragments, because of their low cost and convenience. In many instances, product yields have been less than adequate and intrinsic and extrinsic variables have been investigated in an effort to improve yields. This review deals with various aspects of antibody expression in E. coli with a particular focus on single-domain antibodies.