Photoelectron fluxes were calculated by using the two-stream technique and were compared with measurements obtained by the photoelectron spectrometer on Atmosphere Explorer C and E. Comparisons of theoretical and experimental results for a variety of conditions have shown that the calculated and measured photoelectron fluxes agree well at low altitudes, and even at higher altitudes, where transport effects are important, the agreement is not unreasonable considering all the uncertanties involved. Therefore (1) the numerical techniques presently available to calculate photoelectron fluxes are in reasonable agreement with experimental data, (2) the EUV fluxes measured on Atmosphere Explorer are consistent, within the given uncertainties, with the measured photoelectron fluxes, (3) we need better differential photo-ionization and scattering cross-section data for improved flux calculations, and (4) better high-altitude comparisons require measurements of the pitch angle distribution.