The light-induced high-spin → low-spin relaxation for the Fe(II) spin-crossover compounds [Fe(btpa)](PF₆)₂ and [Fe(b(bdpa))](PF₆)₂ in solution, where btpa is the potentially octadentate ligand N,N,N‘,N‘-tetrakis(2-pyridylmethyl)-6,6‘-bis(aminomethyl)-2,2‘-bipyridine and b(bdpa) is the analogous hexadentate ligand N,N‘-bis(benzyl)-N,N‘-bis(2-pyridylmethyl)-6,6‘-bis(aminomethyl)-2,2‘-bipyridine, respectively, has been studied by temperature-dependent laser flash photolysis. [Fe(b(bdpa))](PF₆)₂ shows single-exponential ⁵T₂ → ¹A₁ relaxation kinetics, whereas [Fe(btpa)](PF₆)₂ exhibits solvent-independent biphasic relaxation kinetics. The fast process of [Fe(btpa)](PF₆)₂ with a rate constant, k_HL, of 2.5 × 10⁷ s^-1 at 295 K and an activation energy, E_a, of 1294(26) cm^-1 in methanol can be assigned to the ⁵T₂ → ¹A₁relaxation as well. The slow process with a k_HL(295 K) of 3.7 × 10⁵ s^-1 and a E_a of 2297(32) cm^-1 in methanol - which is the slowest light-induced relaxation process observed so far for an Fe(II) spin-crossover complex in solution - is assigned to a coupling of the ⁵T₂ → ¹A₁relaxation process to a geometrical rearrangement within the pendent pyridyl arms.