The title complex, [Pd(C2H2N3S2)2(C18H15P)2]·2C2H6OS·0.5H2O, was obtained from the reaction of trans-[(Ph3P)2PdCl2] with 5-amino-1,3,4-thia­diazole-2-thione (SSNH2) in a 2:1 molar ratio. The PdII atom, located in a crystallographic center of symmetry, has a square-planar geometry with two triphenyl­phosphine P-coordinated mol­ecules and two SSNH2 ligands with the S atoms in a trans conformation. The latter ligand exhibits N—H⋯N hydrogen-bonding contacts formed by the amino group with the thia­diazole ring, generating a chain along the c axis. The asymmetric unit contains one half of the complex mol­ecule along with disordered dimethyl sulfoxide and water mol­ecules.