We report calculated elastic and inelastic cross sections for low-energy electron collisions with methylsilane, CH3SiH3, obtained using the Schwinger multichannel method. The elastic cross sections, obtained within the static-exchange approximation, are compared with elastic results for C2H6 and Si2H6. Electron-impact excitation cross sections were computed for sixteen electronic states arising from excitation out of the two highest-lying valence orbitals. The dissociation of the lowest few states was examined through limited electronic-structure calculations, which indicated that the 2 (1,3)A(1) states dissociate to CH3SiH+H-2 while the 1 E-1,E-3 states dissociate to CH3+SiH3. (C) 2003 American Institute of Physics.