The Boltzmann collision term in strongly magnetized plasma S. A. Koryagin Institute of Applied Physics, RAS, 46 Uljanov st., Nizhni Novgorod 603600, Russia We generalize the Boltzmann form of the collision term for collisions in magnetic field. We analyze electron-ion collisions in the case when electron cyclotron period is less than the duration of a close collision in isotropic plasma. The differential cross section is obtained for this case. The effect of drastic change in Coulomb collision frequency on the transfer of cyclotron radiation in photospheres of magnetic white dwarfs is discussed.