Various preparation conditions were investigated to evaluate their effect on the dispersion of Pt on zeolite KL. The highest dispersion was obtained by calcining in O 2 at about 350 °C. Calcining in N 2 or H 2 resulted in lower dispersions. Irrespective of the gas atmosphere, heating at 600 °C resulted in sintering of the Pt. The duration of calcination, whether at 350 °C or 600 °C, had little effect on Pt dispersion. The rate at which the temperature was increased up to the calcination temperature and the rate of the O 2 flow also had no effect. Subsequent to identical calcination procedures, reduction with H 2 resulted in much higher Pt dispersions than reduction with CO. Below 350 °C the temperature of the H 2 reduction did not have a marked effect on dispersion. At the 1.5% Pt level, different loading techniques, viz., liquid ion exchange, solid-state ion exchange, and incipient wetness impregnation, resulted in similar Pt dispersions. There was a good correlation between the percentage of Pt dispersion and n -hexane conversion in the aromatization reaction. Pt dispersions were determined by CO chemisorption, and the observed trends were confirmed by TEM. Hydrogen chemisorption was a less satisfactory method of measuring dispersion. © Elsevier Science Inc. 1997