To meet the need for a portable field test kit for the accurate determination of trace levels of dissolved copper in jet fuel, a spectrophotometric-based approach has been developed. A combination of a metal complexation ligand (bathocuproine), reducing agent (ascorbic acid), and solubilizing agent (ethanol) is introduced directly to jet fuel samples emanating from a number of different sources and handling histories, and the total copper content is accurately determined. The detection limits, based on a signal/noise ratio of 3:1, were 6.2 mug/L with a benchtop dual beam spectrophotometer and 7.5 mug/L with a portable, fiber optic spectrometer. Since bathocuproine, itself, has some reducing capability, the concentration of Cu(I) in these jet fuels could not be differentiated from the concentration of Cu(II).