Precise control of doping in single nanowires (NWs) is essential for the development of NW-based devices. Here, we investigate a series of MBE-grown NWs with (-type) and (-type) doping using high-resolution cathodoluminescence (CL) mapping at low and room temperatures. CL spectra are analyzed selectively in different regions of the NWs. Room-temperature luminescence is fitted with the generalized Planck law and an absorption model, and the bandgap and band tail width are extracted. For -doped NWs, the bandgap narrowing provides a quantitative determination of the hole concentration ranging from about to , in good agreement with the targeted doping levels. High-resolution maps of the hole concentration demonstrate the homogeneous doping in the pure zinc-blende segment. For -doped NWs, the electron Fermi level and the full width at half maximum of low-temperature CL spectra are used to assess the electron concentration to approximately to . These findings confirm the difficulty in obtaining highly doped -type NWs, maybe due to doping compensation. Notably, signatures of high concentration [(5–9)] at the very top of NWs are unveiled.