The influence of total pressure, temperature and H-2:N-2 molar ratio on both catalytic activity and selectivity during n-hexane isomerization over platinum impregnated on tungsten-oxide-promoted zirconia was studied. It was found that the increase in pressure up to 6 kg cm(-2) increases catalytic activity. The higher the temperature, the larger the catalytic activity. Selectivity to isomers remains practically constant, only decreasing when temperature is increased above 225 degrees C. In the absence of hydrogen, a rapid deactivation is observed as well as a different product distribution.