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.