The title compound, C37H34FN3OS2·C2H6OS, was obtained by the Knoevenagel condensation. The thiazolidine ring is essentially planar (r.m.s. deviation = 0.025 Å) and forms dihedral angles of 4.2 (3), 68.60 (14) and 39.57 (15)° with the attached thioamide group, p-tolyl group benzene ring and fluoro-substituted benzene ring, respectively. The exocyclic double bonds are in a Z configuration. In the crystal, the dimethyl sulfoxide solvent molecule is connected to the main molecule via an N—H...O hydrogen bond. Weak C—H...O hydrogen bonds link the components of the structure into a two-dimensional network parallel to (10-1). Weak intramolecular C—H...S hydrogen bonds are also observed. The crystal is an inversion twin with a ratio of twin components 0.78 (2):0.22 (6).