It has been demonstrated that the magnetic effect of the amide group of sterically fixed N-acyl-piperidines affects essentially the protons of N-alkyl groups, provided the carbonyl group is in cis-position. The magnetic field acts shielding or deshielding. The corresponding regions are shown in a general model. Equatorial protons ofα-methylene groups in N-acyl-piperidines are in the deshielding region, corresponding axial protons are in the shielding region. The protons of freely rotating N-methyl groups pass in turn both regions. The resulting mean shows, that shielding predominates. The knowledge of the magnetic anisotropy enables the assignment of the conformation of N-acetyl-2-methyl-piperidine which prefers a conformation with an axial methyl group. In 2-methyl-N-trifluoracetyl-pyrrolidine and N-isopropyl-isoquinuclidone the methine protons are situated in the amide plane