Fe(II) complexes with 4-R-1,2,4-triazoles of compositions FeL3A2 · nH2O (where L is 4-propyl-1,2,4-triazol; A is Br- (n = 4), CF3SO3 - (n = 5)), and FeL2A2 · nH2O (where L are 4-ethyl-, 4-propyl-, 4-isopropyl-1,2,4-triazoles (Ettrz, Prtrz, Iprtrz, respectively), A = NCS-, NO3 - (n = 0-2)) were synthesized. Magnetochemical studies revealed that FeL3A2 · nH2O complexes exhibit reversible spin transition (ST) 1 A 1 ⇄ 5 T 2 that is accompanied by thermochromism (a reversible change of color rose ⇄ white). The temperatures of direct (T s↑) and reverse (T s↓) spin transitions are, respectively, 252 and 247 K for Fe(Рrtrz)3Br2 · 4H2O and 207 and 202 K for Fe(Рrtrz)3(CF3SO3)2 · 5H2O. Dehydration of the complexes is attended by significant changes in the type and temperatures of ST.