Herein we describe the synthesis and characterization of new sulfonated and carboxylated poly(propyleneimino) (PPI) dendrimers with the ethylenediamino (EDA) core, at generations 1, 2 and 3. By means of UV-Vis and EPR spectroscopy, using Cu²⁺ as a probe, we concluded that these dendrimers show a specific pattern in the coordination of metal ions. In agreement with the UV-Vis studies, EPR spectra of carboxylated compounds are constituted by 3 different signals which appear and then disappear with increasing copper concentration, corresponding to the saturation of different copper complexation sites. At the lowest copper concentration up to a 1 : 1 molar ratio between Cu^II and the dendrimer, the spectrum is characteristic of a CuN₂O₂ coordination at the core of the dendrimer. The spectrum appearing at higher Cu^II concentrations indicates a peripheral location of the ions coordinating one nitrogen and 3 oxygen atoms in a square planar geometry in restricted mobility conditions. For the highest concentrations tested, copper ions are confined at the external dendrimer surface with CuO₄ coordination. For sulfonate systems, the EPR results are in line with a weaker interaction of Cu^II with the nitrogen sites and a stronger interaction with the oxygen (SO₃⁻) groups with respect to the interactions measured by EPR for carboxylate systems.