A series of Iron (Fe(II)) and manganese (Mn(II)) complexes of 1,3-substituted 5-(2-benzothiazolyl)formazans are reported. The crystal structures of the Fe(II) and Mn(II) complexes of 1,3-diphenyl-5-(2-benzothiazolyl) formazan are very similar and both contain a coordination sphere of four five-membered rings involving the N1 and N3 nitrogen atoms of the formazan chain and the N2 of the heterocyle resulting in a distorted octahedral structure in both cases. The distortions arise primarily from the spatial requirements of the bulky phenyl substitutents.