Intrinsic properties of conducting polymers, such as oxidation potential and band gap, are very important for designing new materials with improved properties. Computational chemistry offers suitable tools capable of predicting these quantities. This work presents electrochemical information about accurate oxidation potentials of oligothiophenes and polymer band gap. These are compared to theoretical predictions based on electronic structure calculations at Density Functional Theory levels, coupled with self-consistent reaction field. All computational protocols gave a qualitative prediction of the experimental trend. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1723-1733, 2011