State-selective fragmentation dynamics for excited fragments and ionic fragments of gaseous and condensed Si(CH3)2Cl2 following Cl 2p and Si 2p core-level excitations have been characterized. The Cl 2p-->15a1* excitation of Si(CH3)2Cl2 induces significant enhancement of the Cl+ desorption yield in the condensed phase and the Si(CH3)+2 and SiCH+3 yields in the gaseous phase. The core-to-Rydberg excitations at both Si 2p and Cl 2p edges lead to enhanced production of the excited fragments. These complementary results provide deeper insight into the origin of state-selective fragmentation of molecules via core-level excitation.