The phases formed by 10, 20, 30, 40 and 50 mg ml-1 solutions of a compound, named RWJ-47428, in water have been studied with optical polarizing microscopy and X-ray diffraction. All solutions were found to exhibit the nematic liquid crystalline phase over a wide temperature range. Changes in optical textures showed a transition to the isotropic phase above 130°C in the most concentrated solution. The dimensions (length and width) of the orienting unit were determined to be 22 Å and 4.9 Å. Higher concentration samples exhibit both the nematic and the lamellar phases.