The mechanism of the synthesis of phenyltrichlorosilane from trichlorosilane and chlorobenzene by gas phase condensation was studied. A kinetic model with 28 species and 56 elementary reactions was established, which was validated by experimental results from a tubular reactor under wide reaction conditions. The mole fraction profiles of the reactants and products from the kinetic model were in good agreement with the experimental results. This gas phase condensation reaction mainly followed an insertion mechanism of dichlorosilylene into the C-Cl bond to form C6H5SiCl3. A reaction flux analysis showed that 99% of C6H5SiCl3 was generated from the insertion reaction, 74% of SiCl3H was decomposed into SiCl2 and 91% of SiCl2 was inserted into C6H5Cl to form C6H5SiCl3. The proposed mechanism and kinetic model are useful for developing and designing commercial reactors to produce phenyltrichlorosilane. (C) 2013 Elsevier B.V. All rights reserved.