We present a strong improvement of the electronic transport properties in the Fe 2 VAl Heusler alloy obtained in thin-film form by a co-sputtering process. The power factor is improved when deposition occurs at temperatures close to 873 K and when the composition is tuned using a co-sputtering process. High values up to 5.6 mW/K 2 m are obtained for n-type films deposited at 873 K, which is up to now a record for self-substituted Fe 2 VAl thermoelectric thin films. The influence of co-sputtering conditions on atomic composition and the substrate effect on electronic transport properties are also presented.