Ca3Co4−xTixO9 polycrystalline thermoelectric ceramics with small amounts of Ti have been prepared by the classical solid state method. X-ray diffraction data have shown that Ca3Co4O9 is the major phase, with small amounts of the Ca3Co2O6 one. Moreover, they show that Ti has been incorporated into these two phases. Electrical resistivity decreases, compared with the values for undoped samples, until 0.03-Ti doped ones. Further Ti addition produces an increase of resistivity with respect to the 0.03 Ti doped samples. Seebeck coefficient does not appreciably change in all the measured temperature range, independently of Ti content. The improvement in electrical resistivity leads to about 55 % higher power factor values for the 0.03 Ti-doped samples than that obtained in the undoped ones. The maximum power factor at 800 °C, around 0.33 mW/K2 m, is slightly higher than the obtained in higher density samples, clearly indicating the good thermoelectric performances of these doped samples.