The amounts of five polynuclear aromatic hydrocarbons-fluoranthene, pyrene, benzo(a)anthracene, benzo(k)fluoranthene, and benzo(a)pyrene-extracted by six solvents with four extraction techniques have been determined for diesel exhaust particulate collected on Teflon-coated glass fiber filters. Samples were analyzed by high pressure liquid chromatography with fluorescence detection. Toluene and methylene chloride gave higher recoveries than methanol, isopropanol, acetonitrile, and acetone for benzo(a)anthracene, benzo(k)fluoranthene, and benzo(a)pyrene. Soxhlet extraction for two hours (approximately 48 cycles) with toluene or acetonitrile was more effective than simple mechanical agitation, ultrasonic agitation for 15 minutes or immersion in refluxing ‘solvent’ for two hours.