Migration reactivities of σ-bonded organo-iron and -cobalt porphyrins were examined as a function of the compound oxidation state. Migration rates were determined for both the one-electron and two-electron oxidized species produced in the electron-transfer oxidation with different oxidants in acetonitrile at 298 K. The investigated compounds are represented as [(OETPP)Fe(R)]n+, where n = 1 or 2, OETPP = the dianion of 2,3,7,8,12,13,-17,18-octaethyl-5,10,15,20-tetraphenylporphyrin, and R = C6H5, 3,5-C6F2H3, or C6F5, and as [(TPP)Co(R)]n+, where n = 1 or 2, TPP = the dianion of 5,10,15,20-tetraphenylporphyrin, and R = CH3 or C6H5. The rapid two-electron oxidation of (OETPP)FeIII(R) occurs with [Ru(bpy)3]3+ (bpy = 2,2′-bipyridine) to produce [(OETPP)-FeIV(R)]2+. The formation of this species is followed by a slow migration of the σ-bonded R group to a nitrogen of the porphyrin ring to give [(N-ROETPP)FeII]2+ and then by a rapid electron-transfer oxidation of the migrated product with [Ru(bpy)3]3+ to yield [(N-ROETPP)FeIII]3+ as a final product. When [Ru(bpy)3]3+ is replaced by a much weaker oxidant such as ferricenium ion, only the one-electron oxidation of (OETPP)Fe(R) occurs to produce [(OETPP)FeIV(R)]+. A migration of the R group also occurs in the one-electron oxidized porphyrin species, [(OETPP)FeIV(R)]+, to produce [(N-ROETPP)FeII]+, which is rapidly oxidized by ferricenium ion to yield [(N-ROETPP)FeIII]2+. The migration rate of the R group in [(OETPP)FeIV(R)]+ is about 104 times slower than the migration rate of the corresponding two-electron oxidized species, [(OETPP)FeIV(R)]2+. The migration rate of the σ-bonded ligand of [(TPP)CoIV(R)]+, produced by the one-electron oxidation of (TPP)CoIII(R) with [Fe-(phen)3]3+ (phen = 1,10-phenanthroline) is also about 104 times slower than the migration rate of the R group in the corresponding two-electron oxidized species, [(TPP)CoIV(R)]2+, which is produced by the two-electron oxidation with [Ru(bpy)3]3+. A comparison of the migration rates with the oxidation states of the porphyrins indicates that the migration occurs via an intramolecular electron transfer from the R group to the Fe(IV) or Co(IV) metal of the organometallic porphyrin.