In the title compound, [Fe-II(C44H24Cl4N4)(C5H9N)(2)] or [Fe-II(TClPP)(t-BuNC)(2)] [where TClPP and t-BuNC are 5,10,15,20-tetrakis(4-chlorophenyl)porphyrinate and tert-butyl isocyanide ligands, respectively], the metal ion lies on an inversion center and is octahedrally coordinated by the N atoms of the porphyrin ring in the equatorial plane and by carbon atoms of the trans t-BuNC ligands in the axial sites. The Fe-N bond length of 2.0074 (14) angstrom suggests a low-spin complex (S = 0). The crystal packing of the title compound is sustained by C-H center dot center dot center dot Cl, C-H center dot center dot center dot N and C-H center dot center dot center dot Cg (Cg = the centroid of a pyrrole ring of the TClPP porphyrinate) interactions, leading to a three-dimensional network. The Hirshfeld surface (HS) analysis indicates that 61.4% of the intermolecular interactions are from H center dot center dot center dot H contacts while other contributions are from C center dot center dot center dot H/ H center dot center dot center dot C, O center dot center dot center dot H/H center dot center dot center dot O and N center dot center dot center dot H/H center dot center dot center dot N interactions, which comprise 21.3%, 13.3% and 3.6% of the HS, respectively.