Barium hexaaluminate was prepared by coprecipitation method and used as support for nickel catalysts, with 7 and 14 wt% of NiO. After calcination at 1,200 A degrees C the hexaaluminate support consisted of different crystalline phases with specific surface area of 22 m(2) g(-1). The catalysts exhibited nickel reduction peaks in the range of 400-540 A degrees C. The catalysts were evaluated in steam reforming of different tar model compounds: benzene, toluene and naphthalene (in solution with toluene). The conversions obtained in benzene and toluene reforming at 650 A degrees C were quite similar, while naphthalene is much more difficult to be converted and inhibits toluene conversion at 800 A degrees C. Both catalysts showed good stability with time on stream despite the high amount of carbon deposit. The coke amount and morphology are dependent on the nature of aromatic compound. .