In this study, nanostructured CuNiCoZnAl high entropy alloy was synthesized by mechanical alloying. X-ray diffraction and transmission electron microscopy results showed that this quinary alloy has a FCC single phase solid solution and crystallite size about 15 nm. Energy dispersive spectroscopy results also confirmed the absence of impurities and verified the chemical composition of the alloy. Moreover, the alloy morphology was evaluated using scanning electron microscopy. Results of calculation of parameters such as melting point, mixing enthalpy change, mixing entropy change, atomic size difference, electronegativity difference and valence electron concentration of the alloy were in good agreement with the criteria for phase stability of high entropy alloys, and formation of high entropy alloy consisting of FCC solid solution could be predicted. Thermodynamic analysis of Cu-Ni-Co-Zn-Al alloy system using extended Miedema model confirmed the experimental results and predicted the solid solution as the first phase that formed. Thermal analysis of alloy using differential scanning calorimetry technique revealed that the solid solution phase was the stable phase from room temperature (~25°C) up to the melting point (~1150°C). In spite of phase transformations during this temperature range, intermetallic compounds and amorphous phase were not formed. The effect of mechanical alloying conditions and energy calculations showed that by increasing the velocity of ball milling and using the balls with different radii (instead of the balls with similar radii) energy transferred during ball milling would increase up to 1.7 times and provides the condition for CuNiCoZnAl alloy formation. Consolidation of the alloy powder was performed by cold press (in the case without a binder, and the sample containing sodium metasilicate) and spark plasma sintering. Investigation showed that cold press caused poor sintering and high porosity in the samples; therefore it could not be a suitable method for consolidation of the CuNiCoZnAl alloy powder, while spark plasma sintering led to the proper compression and low porosity. Also the nanostructure of bulk sample could be preserved by spark plasma sintering. Therefore CuNiCoZnAl alloy obtained from spark plasma sintering was selected for evaluation of mechanical behavior. Investigation of mechanical behavior using nanoindentation, indicated hardness value of 659.350±18 HV and elastic moduli of 186.240±17 GPa respectively. Also Vickers microhardness of the alloy was 598.69±31 HV. The evaluation of wear behavior of the alloy using pin-on-disk wear test indicated that the dominant wear mechanism of CuNiCoZnAl alloy wa adhesive wear. The sample weight loss at 700 m showed that wear rate decreased quickly at the begining with high wear rate and then became stable indicating a steady state wear. Constant friction coefficient without volatility indicated a uniform wear behavior of the alloy. Keywords: High entropy alloy, CuNiCoZnAl, Nanostructure, Mechanical alloying.