  Superconductivity in Mo3Sb7 is analyzed using the combined electronic
structure and phonon calculations, and the electron--phonon coupling constant
\lambda_{ph}=0.54 is determined from first principles. This value explains the
experimental value of the superconducting critical temperature T_c=2.2 K. The
possible influence of spin fluctuations and spin gap on the superconductivity
in Mo3Sb7 is discussed, and electron--paramagnon interaction is found to be
weak.
