Beta zeolites with average crystal sizes of 2 pm and 0.6 pm were synthesized and characterized. The catalytic activities of the synthesized catalysts were studied in the isomerization of n-butane to iso-butane. The effect of reaction temperature, catalyst pretreatment, and carrier gas was investigated for the conversion of n-butane and selectivity to iso-butane. The Pt-H-Beta catalyst in presence of hydrogen as a carrier gas led to higher conversion of n-butane and selectivity to iso-butane than nitrogen. This is an abstract of a paper presented at the 13th International Zeolite Conference (Montpellier, France 7/8-13/2001).