The kinetics of thermal decomposition of cage hydrocarbons, specifically exo-tricyclo[5.2.1.02.6]decane (exo-TCD) and exo,endo-tetracyclo[5.3.1.02,6.08,10]undecane (TCU-1, a monocyclopropanated analog of exo-TCD), as well as their mixture (1 : 3 w/w) has been investigated. These compounds were compared in terms of thermal stability. The molar concentrations of the resultant gaseous products were determined experimentally. The equilibrium composition of the decomposition products was quantified, and the thermal effects of the thermal decomposition under thermodynamic and kinetic reaction control were identified.