The composition, stability and equilibria of ternary complexes of Cd(II) with adipate (Adp) as primary ligand and 1,3-diaminopropane (DAMP) as secondary ligand have been studied using differential pulse (d.p.) polarography. The results reveal the presence of three ternary complexes with stoichiometries 1:1:1, 1:1:2, and 1:2:1. Also, the composition and stability of binary species have been determined. The reduction of simple and mixed ligand complexes is reversible and diffusion controlled. The formation constants of mixed complexes were calculated and compared with the observed values.