In this work, a study of the effect of the pH used in the elaboration process of solid biopolymer electrolyte films of cassava starch on its electroactivity is presented.For the preparation process of the films, mixtures of starch, plasticizers and lithium perchlorate prepared at different pH values were used.Acid pH was achieved by the addition of hydrochloric acid and the basic pH with the addition of sodium hydroxide.The electroactivity of the films was evaluated by the cyclic voltammetry technique, and infrared spectroscopy was used to characterize them.The results showed that at strongly acidic pH, the films ware brittle and had low mechanical stability, while the films prepared at moderately acid, neutral and basic pH, the films showed good flexibility and good mechanical stability.The infrared spectroscopy allowed to establish a correlation between starch crystallinity and the elaboration pH, indicating that at lower pH lower crystallinity.The results of the electrochemical studies allowed to establish that the intensities of the peaks in the signals were greater in acidic pH and the peak potentials had greater variability in pH less than 5 and greater than 9.In addition, the pH of processing affected the stability of the electrochemical signals.As a conclusion, it could be established that the synthesis pH had a great effect on the crystalline structure of the starch in the films and this affected its mechanical stability and its electrochemical response.