KY(WO4)(2) single crystals were grown by the Bridgman-Stockbarger method. Due to the existence of two polymorphic forms the elaboration was performed below the transition line using different fluxes chosen in the WO3-Y2O3-K2O ternary system. The compound is not stoichiometric and the crystal composition depends on the flux. We verified that these differences of composition did not alter the structure and the spectroscopic properties. A structure study was also performed on single crystals and powder in order to check recent observations about the validity of the proposed structure.