The title compound, [Fe(C5H5)(C21H24NPS)]I·CHCl3, is built up from a (ferrocenylmeth-yl)trimethyl-ammonium cation, a iodine anion and a chloro-form solvent mol-ecule, all residing in general positions. The N atom of the ammonium group is displaced by 1.182 (2) Å from the plane of the substituted cyclo-penta-dienyl (Cp) ring towards the Fe atom, whereas the C atom attached to the same Cp ring is slightly below this plane by -0.128 (2) Å. These deviations might result from weak agostic interactions between the two H atoms of the CH2 group and the Fe atom.