We analyze optical and ultraviolet spectroscopic observations of the symbiotic star RW Hydrae. This system contains an M2 giant and a hot white dwarf, Th=8O,OOO K, in an eclipsing binary system with an orbital period of 370.2±0.9d. The component masses are Mg≍0.5-2 Msun for the red giant and Mh≍O.3-O.6 Msun for the white dwarf. High-energy photons from the white dwarf ionize the outer atmosphere of the red giant to produce bright emission lines that vary in phase with the orbital period. Densities within the ionized wind range from ne∼1011 cm-3 in the inner portion to ne∼108 cm-3 in the outer portion.