The effect of hydrogen pressure (pH(2)) and temperature (T) was investigated on the hydrogenolytic ring opening of methyl-cyclopentane (MCP) over silica and alumina supported rhodium catalysts. Strong dependence could be seen in the activity and in distribution of ring opening products as a function of reaction conditions. Temperature and hydrogen pressure did not affect the position of the first C-C bond rupture. However, the final ring opening product distribution was largely influenced by the reaction conditions due to the different ability of intermediates to undergo further hydrogenolysis.