The effects of pulsed electric and magnetic fields on the resistivity of La(0.67)Ca(0.33)MnO(3) and La(0.7)Sr(0.3)MnO(3) thin films were investigated using electric fields with amplitudes up to 3 0 kV/cm. The magnetic field pulse amplitude was 0.3 T. Experimental results show that the electric and magnetic fields in this case significantly reduces the resistance of the film. It was concluded that most probably the electric field affects the energy of the charge carriers, increasing their possibility to penetrate through potential barrier between Mn ions.