CF/PAni composites were synthesized using the polymerization chemistry. Three different deposition times were used in the synthesis, such as: 30, 60 and 90 min. The morphology and the structure of composites were analyzed by SEM and Raman spectroscopy, respectively. The influence of the mass of polymer deposited on the carbon fiber, with respect to the values of specific capacitance (C-sp) was analyzed by electrochemical experiments. The optimum value of the C-sp was obtained for CF/PAni-30 min (C-sp = 188 Fg (1)). This fact is related to the lower charge transfer resistance, due to its more homogeneous morphology and thin layer polyaniline. (C) 2011 Elsevier B.V. All rights reserved.