A simple, fast and reliable spectrophotometric method for the determination and microextraction of trace amounts of uranium using chromotrope 2R as a chelating agent and 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) was used as an extractant solvent. Influence variables such as pH, volume of ligand and IL were inspected by full factorial design. In the view of Pareto chart a contour plot was studied to examine the significant variables and their interactions. The detection limit and the preconcentration factor were found to be 0.87 and 50 mu g L-1, respectively. The developed method was successfully applied to ore samples.