Bendroflumethiazide, or 3-benzyl-6-(trifluoromethyl)-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide, is reported to crystallize as 1:1 solvates with acetone, C(15)H(14)F(3)N(3)O(4)S(2).C(3)H(6)O, and N,N-dimethylformamide, C(15)H(14)F(3)N(3)O(4)S(2).C(3)H(7)NO. A detailed investigation of the crystal packing and intermolecular interactions is presented by means of Hirshfeld surface analysis. This analysis confirms the atomic positions of methyl H atoms of the solvent molecules that were inferred from the X-ray data and provides a useful tool for structure validation.