This work is an investigation on neutral electrolytes for electroless copper and copper (I) oxide plating of anodized aluminum. The plating electrolytes were based on copper (II) sulfate and phosphorous acid (H3PO3) as a reducing agent. It was investigated the influence of factors, such as Cu2+ concentration (0.024–0.048 mol/L) and pH (5–8) of the copper plating bath on the thickness, morphology and phase composition of the coatings, as well as kinetics of the electroless coating growth. The thickness and deposition rates of the coatings were determined gravimetrically and by X-ray fluorescence analysis. Electroless layer morphology was studied by optical and scanning electron microscopy. Crystallographic information and element composition depth profiles were examined by XRD and EDX analyzes respectively. Optimal deposition rates were achieved with electrolytes with Cu2+ concentration of 0.04 mol/L. Metallic copper layers were only formed at pH 5, while copper (I) oxide (Cu2O) was formed at higher pH and the underlying mechanism was proposed.