Three cadmium coordination polymers, namely, { [CdL-(OAc) and [CdL-(OAc) 2 (H 2 O)] n (3), were synthesized by an exoditopic 1,4-bis(4pyridyl)-2,3-diaza-1,3-butadiene Schiff base ligand (L) and cadmium acetate in the presence of different solvent systems. Single-crystal X-ray diffraction, powder X-ray diffraction, and thermogravimetric analysis showed that 1D ladder pseudopolymorphic compounds (1 and 2) transformed to the solvent-free 1D linear compound 3 through a rare case of water absorption from air at room temperature. Interestingly, compound 3 was transformed to compound 1 through a dissolution− recrystallization structural transformation process. The results illustrated that solvents and humidity have an important role in the formation of pseudopolymorphs with the same or different structural motifs.