Abstract: Based on the vectorial Rayleigh-Sommerfeld diffraction formula, the analytical expressionons for nonparaxial off-axis radially polarized Gaussian beams propagating in free space are derived. The nonparaxial propagation properties of off-axis radially polarized Gaussian beams are studied, and compared with the corresponding paraxial results. It is shown that the f parameter, off-axis coefficient and propagation distance play important roles in the nonparaxial propagation properties of the off-axis radially polarized Gaussian beams. Moreover, when the propagation distance is farther, the off-axis radially polarized beams exhibit better off-axis healing property.