We report a very simple precipitation route to prepare a layered perovskite-type structure, tungsten trioxide hydrate (TTH), with the nominal chemical formula of WO3 center dot 1.3H(2)O ( 1/2H(2)W(2)O(7)center dot 1.6H(2)O), using aqueous Na2WO4 and SrCl2. Our investigation shows that the concentration of HCl used to dissolve the SrCl2 plays a crucial role in the stabilization of different structure types of layered TTHs. Highly acidic SrCl2 (dissolved in 9 M HCl) solution yields an orthorhombic layered TTH of WO3 center dot 2H(2)O, while SrCl2 dissolved in 3 M HCl appears to give an A-site-deficient Ruddlesdon-Popper (RP) related double-perovskite-type layered structure (DOLS-TTH). A well-known scheelite-type structure is obtained under weakly basic conditions (pH = 10.3 for Na2WO4(aq), 7.0 for SrCl2(aq)). Previously, RP-type a DOLS of H2W2O7 center dot 0.58H(2)O was prepared, using an acid-leaching method, from the corresponding n = 2 member of the layered Aurivillius phase (AP) Bi2W2O9. Powder X-ray diffraction showed the formation of layered RP DOLS with a large d spacing similar to 12.5 angstrom, which is consistent with acid-leaching (Kuto et al. Inorg. Chem, 2003, 42, 4479-4484; Wang et al. J. Solid State Chem. 2007, 180, 1125-1129) and exfoliation (Schaak et al. Chem. Commun. 2002, 706-707) methods for synthesized TTHs. The proposed DOLS-TTH structure of newly prepared TTHs was further confirmed by an intercalation reaction using n-octylamine (CM). A transmission electron microscopy study showed the formation of nanosized particles, and scanning electron microscopy coupled with energy dispersive X-ray analysis showed the absence of Na and Sr in the air-dried, as-precipitated products under acidic conditions. The bulk electrical (proton) conductivity of presently prepared TTHs was found to be on the order of 10(-4)-10(-3) S/cm at room temperature in wet N-2.