The low- and high-resolution mass spectra of CpCr(NO) 2Cl (Cp = cyclopentadienyl) and of Cp 2Cr 2(NO) 2(μ-NO)(μ-X) compounds with X = No, NH 2, NHCH 3, N(OH)-t-C 4H 9, N=CH 2, and N=CH-n-C 3H 7 have been measured; complete fragmentation diagrams have been obtained by detection of metastable decompositions using a linked scan technique. The degradation of the dinuclear complexes is essentially determined by the bridging ligand X. The numerous rearrangements are partially characterized by transfer of the nitrosyl nitrogen onto other ligands with formation of CrO bonds.