This paper reports the first attempt of the Pt-catalyst-assisted MOVPE growth of InN. In order to enhance NH3 decomposition at a relatively low growth temperature (similar to 550 degrees C), Pt is used as a catalyst. The catalyst is installed in the NH3 introduction tube in the MOVPE reactor and the tube is located just above the susceptor to be heated. Compared with InN films grown without the catalyst, the samples grown with Pt catalyst show improved electrical properties; a carrier concentration in the order of 10(18) cm(-3) and a Hall mobility as high as 1350 cm(2)/Vs are obtained. The crystalline quality is also improved by employing the catalyst and a tilt fluctuation as low as 8.6 arcmin is obtained for a sample grown on a GaN/sapphire template. It is confirmed that for InN films grown at 550 degrees C with Pt catalyst, the electrical and crystallographic properties are also improved with increase in thickness. These results indicate that the growth at around 550 degrees C with the Pt catalyst is performed under the circumstances where NH3 is effectively decomposed, whereas the deterioration of InN during growth is significantly suppressed. (C) 2010 Elsevier B.V. All rights reserved.