We performed the optimization of conditions in chemical bath deposition using the design of experimental methodology. Factorial design (2(3)) was used for finding the optimal conditions of preparing vanadium(V) oxide xerogel thin films with better electrochromic properties suitable for electrochemical applications. The thin films were prepared by acidification of NH4 VO3 aqueous solution with chemical bath deposition. The factors and selected values we considered were as follows: the deposition time (10 and 20 min), the deposition temperature (70 and 80 degrees C), and the mass of ammonium metavanadate (0.3 and 0.5 g). UV-vis spectrometry was used for recording the transmittance variance, Delta T, as the property of interest for modeling in this work. Increasing the deposition temperature and time values led to an increase in the value of Delta T at 800 nm wavelength, but the mass of NH4 VO3 showed the opposite effect. Modeling performed using a 2(3) factorial design showed that the concentration of the ammonium metavanadate was the single most important factor.