The contribution of bremsstrahlung, annihilation, and fluorescence radiation to the spectra of scattered gamma radiation and to the dose buildup factors has been investigated as a function of source energy, atomic number, and sample thickness over an energy range of 0.1 to 8 MeV. The computations were performed with the one-dimensional transport code ASFIT modified to take into account all the secondary radiations. The required mathematical formulation, along with representative results obtained for uranium, lead, iron, and water, typifying materials of very high, high, medium, and low atomic number, are presented and discussed. A noticeable effect of including bremsstrahlung sources is the general softening of the scattered radiation spectra inside the medium and at the exit. This effect is more pronounced in materials of high atomic number. The bremsstrahlung contribution is seen most prominently in the reflection spectra above 0.511 MeV, where the contribution from other processes is insignificant. The effect of annihilation radiation is significant in the region between 0.511 MeV and the K edge, below which the effects of fluorescence radiation overshadow all others. Peaks and discontinuities characteristic of single scatterings of these radiations are seen in the reflection spectra, gradually disappearing with depth in the medium. The effect of fluorescence on the dose buildup factor is spectacular for source energies close to the K edge and falls off rapidly thereafter. The impact of bremsstrahlung, on the other hand, steadily rises with source energy. The influence of annihilation radiation is comparatively modest and is significant only for systems of intermediate atomic numbers.