Geometric and electronic structures of Pd nCu m (m + n ≤ 6) clusters have been investigated by DFT calculations. Pd 4-6 and Pd nCu m clusters with n ≥ 2 and m + n ≥ 4 are spatial whereas Pd 1Cu m and Cu m clusters favor planar shapes. Excess of electron density is shifted towards Pd atom in Pd-Cu bonds and, in spatial particles, towards less coordinated atoms. Bimetallic clusters are usually more stable than monometallic particles of the same size. Stability of bimetallic clusters of the same shape and composition increases linearly with increasing number of Pd-Cu bonds. Pd atoms mix with Cu at every composition, while Cu atoms prefer to segregate at high Cu content.