The feasibility of fungi bioaugmentation in composting of a flare pit soil was studied in. lab-scale composters. The preliminary screening tests, using a range of bulking agents and white rot fungi strains, were conducted to determine, best strain and bulking agent for the main experiments. The initial total petroleum hydrocarbon (TPH) of the flare pit soil was found to tie 16%. The effect of moisture and bulking agent content and the fungi application on biodegradation of hydrocarbons were then evaluated based on a fractional factorial design over a 3-months period. Analysis of the, TPH content of the soil after 98 days (using gravimetric method) showed an average of 29% reduction in most jars. Furthermore, gas chromatograph (GC) analysis of the oil extract from the samples showed 70-99% reduction in the peak area of the selected hydrocarbons. However, statistical analysis of the results did not show any significant effect due to the fungi application. or the change in the moisture content (30-50% range). The results showed that the change in the bulking agent content was marginally significant for the hydrocarbon loss. (C) 2002 Elsevier Science B.V. All rights reserved.