5 5 Mn NMR data are reported for manganese sandwich complexes of the type [(η 5 -C 5 H 5 )Mn(η 6 -C 6 H 6 )] (1), [(η 5 -C 5 H 5 )Mn(η 6 -C 6 H 5 -R )] [R = Me (2) i Pr (3), t Bu (4), Ph (5), SiMe 3 (6a), GeMe 3 (6b), SnMe 3 (6c), PbMe 3 (6d), SMe (6e)], [(η 5 -C 5 H 4 -R)Mn(η 6 -C 6 H 6 )] [R = Me (7), SiMe 3 (8a), GeMe 3 (8b), SnMe 3 (8c), PbMe 3 (8d)], [(η 5 -C 5 H 4 -R)Mn(η 6 -C 6 H 5 -R )] [R = R = Me (9); R = Me, R = Ph (10); R = SiMe 3 , R = Ph (11); R = R = SiMe 3 (12a), GeMe 3 (12b), SnMe 3 (12c), PbMe 3 (12d). SMe (12e), SeMe (12f), R,R = SiMe 2 SiMe 2 (13)], [(η 5 -C 5 R 5 )Mn(η 6 -C 7 H 8 )] [R = H (14), Me (15)] and [(η 5 -C 5 R 5 )Mn(η 6 -C 8 H 1 0 )] [R = H (16), Me (17)]. The chemical shifts δ 5 5 Mn cover a range of ca. 350 ppm for complexes 1 to 12 (δ 5 5 Mn ca - 180 to ca. +170 relative to [MnO 4 ] - aq), whereas further 5 5 Mn deshielding up to ca. 1000 ppm is observed for complexes 14 to 17. Any relationship between the formal oxidation number of Mn and 5 5 Mn magnetic shielding has to be discarded. The large range of the δ 5 5 Mn data for sandwich complexes indicates that 5 5 Mn magnetic shielding depends on the electronic structure of the frontier orbitals which is significantly affected by the ring substituents. Chemical shifts δ 5 3 Cr (relative to [CrO 4 ] 2 - aq) for [Cr(η 6 -C 6 H 6 ) 2 ] (-1206) and [(η 6 -C 6 H 6 )Cr(CO) 3 ] (-1580) have been determined for comparison.