Two new electrochemiluminescence (ECL) reactions in aqueous solution involving cadmium(II) ions are reported. The ECL reaction occurs in the presence of a common co-reactant, tripropylamine (TPA), and either of two organic ligands, 2,2′:6′,2″-terpyridine or 2,2′-bipyridine. The reaction is presumed to arise from the metal-ligand complex and the co-reactant. Conditions for ECL emission were optimised and a calibration graph constructed. Emission was linear over the range 10-1 000 ppb. The calculated limits of detection (LOD) were 8 and 50 ppb using terpyridine and bipyridine, respectively. Comparison with a previously reported reaction involving cadmium(II) ions and 1, 10-phenathroline is made.