We report a Raman scattering determination of the electron density in InN nanowires from the analysis of longitudinal optical-phonon-plasmon coupled modes. A Raman peak assigned to the L− coupled mode is observed in both undoped and doped InN nanowires. This peak exhibits a shift to higher (lower) frequencies in the Si-doped (Mg-doped) nanowires and allows us to estimate the electron density in the nanowires. A significant residual electron density is found in the undoped nanowires, which increases in Si-doped nanowires and is partially compensated in Mg-doped nanowires.