Thermotropic columnar phases are mainly associated with discotic or self-assembled polycatenar (multiple side-chain) mesogens. However, an important class of synthetic polymers, having no such mesogens or no traditional mesogens at all, also exhibit the hexagonal columnar phase. These range from main-chain staple polymers like polyethylene and Teflon to n-alkyl substituted siloxane, silane, phosphazene, peptide and cellulose polymers. A brief review is given with some details of phase behaviour of selected systems.