Metal complexes of DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)−peptide conjugates are increasingly used as targeted imaging and therapeutic radiopharmaceuticals and MRI contrast agents. This review covers the bifunctional derivatives of DOTA, the solution and solid-phase synthesis of DOTA−peptide conjugates, their coordination and chelation chemistry, and the biomedical applications of various DOTA−peptide conjugate metal complexes.