Syntheses, molecular structures and magnetic susceptibilities of three meso-substituted high-spin iron(III) porphyrinate complexes ([Fe(TEtP)(Cl)], [Fe(TPrP)(Cl)], and [Fe(THexP)(Cl)]) are described. It was determined that the inter-ring interactions within each dimeric unit change upon alteration of the alkyl groups at the meso-positions. Magnetic exchange couplings between iron centers of the dimers are in accord with the trends in structural inter-ring geometries. Crystal data for [Fe(TEtP)(Cl)]: a = 10.1710(5) Å, b = 11.309(3) Å, c = 12.170(3) Å, α = 91.774(9) °, β = 113.170(14) °, γ = 112.149(9) °, V = 1165.2(4) Å(3), triclinic, P1̄, Z = 2, R(1) = 0.0844 and ωR(2) = 0.2073 for observed data. Crystal data for [Fe([Fe(TPrP)(Cl)])(Cl)]: a = 13.040(2) Å, b = 15.221(2) Å, c = 14.6681(9) Å, β = 109.997(11) °, V = 2735.9(7) Å(3), monoclinic, P2(1)/n, Z = 4, R(1) = 0.0477 and ωR(2) = 0.1176 for observed data. Crystal data for [Fe(THexP)(Cl)]: a = 10.246(7) Å, b = 12.834(4) Å, c = 17.420(15) Å, α = 69.74(3) °, β = 87.52(4) °, γ, = 84.89(3) °, V = 2140(2) Å(3), triclinic, P1̄, Z = 2, R(1) = 0.1024 and ωR(2) = 0.2659 for observed data.