In this work, we report some preliminary results concerning the fabrication of quaternary copper, indium, gallium, and selenium (CIGS) nanowires that were grown inside the channels of an anodic alumina membrane by one-step potentiostatic deposition at different applied potentials and room temperature. A tunable nanowire composition was achieved through a manipulation of the applied potential and electrolyte composition. X-ray diffraction analysis showed that nanowires, whose chemical composition was determined by energy-dispersive spectroscopy analysis, were amorphous. A composition of Cu0.203 In0.153 Ga0.131 Se0.513, very close to the stoichiometric value, was obtained. These nanostructures were also characterized by photoelectrochemical measurements: They showed a cathodic photocurrent and an optical gap of 1.55 eV.