Sixty-one bidimensionally distributed spectra covering the circumnuclear region of NGC 4161 within a radius of about 6.5 arcsec are presented. The local conditions and the mean velocity field are studied from an analysis of the H-alpha, forbidden N II 6548, 6584, and forbidden S II 6716, 6731 lines. The alignment of the line intensity maps in the direction of higher ionization is confirmed. The electron density is fairly isotropically distributed, although at the inner parts it seems to be more aligned with the major radio axis. Its radial dependence is consistent with an r exp -1.5 law. A relatively low-ionization zone extending about 350 pc is found around the nucleus. The bidimensional distribution of line broadening is anisotropic, roughly transverse to the direction of higher ionization. Although the morphological picture which may be inferred for the circumnuclear region of NGC 4151 is complex, showing anisotropic features, a gradual connection between the galaxy and the nucleus is also found.