Chemical vapor deposition (CVD) of thin films employing Me3CCH=Ta(CH2CMe3)3 and Me3CN=Ta(CH2CMe3)3 as the precursors has been carried out. TaC and TaCN films were deposited at relatively low temperatures (623-923 K). In comparison, using Me3CN=Ta(CH2CMe3)3, the Ta=N bond did not undergo cleavage during the reaction and the N atom was incorporated into the film as nitride. The volatile components evolved were collected and examined by GC-MS, FT-IR, 1H and 13C NMR spectroscopy. Possible decomposition pathways of the tantalum complexes are proposed to rationalize the observation.