A new material based on titanium dioxide modified by tantalum and vanadium has been synthesized. The prepared powders have been deposited to produce gas sensors in the form of thick films through screen-printing technology. The crystalline phase and morphology were examined by XRD and SEM analyses. The results showed that Ta addition inhibited the anatase-to-rutile phase transformation and hindered grain growth during heating, whilst vanadium did the opposite. The sensors have been tested with different gases showing good selectivity; in particular, the samples with greatest content of Ta showed good response to benzene, only slightly influenced by presence of carbon monoxide. © 2004 Elsevier B.V. All rights reserved