Specific interactions of some simple transition metal complexes with DNA are described. Several binding modes and reactions, intercalation, covalent modification, and oxidative cleavage, are discussed and all have in common the specific recognition by metal complexes of subtle features of DNA helical structure. The versatility of the metal center, from its spectroscopic properties to stereochemistry, suggests that coordination complexes may be promising candidates to exploit in the design of drugs and probes for DNA.