Three new [dithiazolylium](x)[M(tdas)(2)] salts are reported (tdas = 1,2,5-thiadiazole-3,4-dithiole). Single-crystal X-ray structures have been obtained for [BDTA](2)[Fe(tdas)(2)Cl] (1) and [BDTA](2)[Ni(tdas)(2)] (2) (BDTA = benzo-1,3,2-dithiazolyl). These are the first examples of integrated anion-cation stacking motifs for [M(tdas)(2)](x-) complexes, as well as the first example of a nondimerized [Fe(tdas)(2)](-) material. [BBDTA][Fe(tdas)(2)] (3) (BBDTA = benzo-bis-1,3,2-dithiazolyl) is also reported, and the magnetic properties of (1) and (3) have been analyzed, showing (1) to be paramagnetic and (3) to have a mixture of dimer and Curie-Weiss behaviour.