A survey of experimental and theoretical results on charge carrier transport in molecularly doped polymers recently obtained is presented. A key transport parameter, drift mobility, measured using conventional time-of-flight techniques is discussed.A number of polymers (polycarbonate, polystyrene, polyimide) and charge transport molecules (pyrazoloquinaline, picrylarylamine, cyanine dyes) is considered. The doped polymer systems exhibited monopolar or bipolar transport depending on electronic properties of both a dopant molecule and polymer matrix. The experimental data are compared with current theoretical models and they well fit a correlated disorder model for a dipole medium when energetic features of the transport molecules are also taken into account. The results are important for development of the most optoelectronic devices (e.g. electroluminescent, photorefractive, photovoltaic, xerographic etc.) whose operation relies critically on charge transport layers.