Total Scanning Fluorescence (TSF) is a rapid and inexpensive technique that can be used for the analysis of polynuclear aromatic hydrocarbons (PAH's). The basis for the use of fluorescence is that, in general, emission/excitation wavelength maxima increase with increasing number of aromatic rings. The output of the TSF analysis is a fluorescence 'fingerprint' consisting of a 3-D emission/excitation intensity contour diagram. This 'fingerprint' can provide information about the content and relative composition of PAH's in samples. To date, this technique has been applied primarily to the analysis of sediment samples collected as part of offshore geochemical exploration programs. In this study, TSF has been evaluated for the rapid screening of oils and soil extracts containing biodegraded crude oil. Analysis of ten crude oils from the southern and western regions of the U.S. shows that their fluorescence characteristics vary widely. These differences can be directly related to varying PAH composition. TSF 'fingerprints' of oil subjected to bioremediation for 52 weeks show systematic differences from those of the unaltered oils. These differences suggest that TSF can be used to measure the abundance and composition of PAH's in samples and to detect loss of PAH's in samples that have undergone biodegradation.