The spectroscopic and dynamical characteristics of electron and hole intraband transitions in small ͑2.7 nm͒, mid-sized ͑4.9 nm͒, and large ͑12 nm͒ GaSe nanoparticles have been studied using polarized femtosecond transient absorption spectroscopy. Assignments of the observed absorptions are made in terms of the known band structure and an effective mass model in which the electron and hole states are described by particle-ina-cylinder states. The energies and relative intensities of the optical transitions are calculated. Assignments of the dynamical aspects of the spectra are facilitated by comparison with time-resolved polarized fluorescence results. The results on the large particles indicate that the transient absorption spectrum is dominated by a size-independent, z-polarized hole intraband transition having an absorption maximum at about 600-650 nm. In addition, there is a smaller contribution from a broad x , y-polarized transition. The small particle spectra exhibit the same z-polarized hole transition and a much more intense x , y-polarized transition. The x , y-polarized absorption is assigned to an electron charge transfer transition from the conduction band to particle surface ͑edge͒ states. The intensity of this transition depends on the particle size and the momentum state ͑⌫ or M͒ of the electron. ⌫ to M electron momentum relaxation is responsible for the fast decay of the x , y-polarized electron transition in the small particles. This fast decay is not present in the large particles because the relative energetics of the M to ⌫ states are size dependent and are in reverse order, compared to the small particles. Relative intensities of the x , y-polarized electron transition may be semiquantitatively understood in terms of overlap considerations calculated from a simple two-dimensional, particle in a nonrigid box model.