The first one-dimensional compounds where [Ln(hfac)₃] (Ln = Gd, Tb, Dy) building blocks are bridged by a verdazyl-based radical, namely 3-imidazolyl-1,5-dimethyl-6-oxoverdazyl, were prepared and their structures elucidated; the magnetic properties were measured for all compounds and quantitatively fitted for Ln = Gd(III) using an alternate chain model leading to J₁ = −1.58 cm⁻¹ and to J₂ = −0.42 cm⁻¹.