Diesel fuel is a common environmental pollutant comprised of a large number of both aromatic and aliphatic hydrocarbons. The microbial degradation of individual hydrocarbons has been well characterized, however, the community dynamics within a system degrading a complex pollutant such as diesel fuel are still poorly understood. The growth capabilities of a diesel-degrading consortium, along with organisms isolated from a contaminated site, were investigated using molecular profiling, isolation, and physiological methods using 10 of the fuel's most abundant constituents as sole carbon sources. The results indicated that the degradation of the fuel's constituents may be shared among the diverse microbial community. Some organisms were capable of growth on the majority of the hydrocarbons tested, whereas others seemed specialized to only a few of the substrates.