During the period June 1 to June 9, 1989, aldehyde and other oxygenated organic compound concentrations were examined at sites 3, 10, and 80 meters northeast of the Vilnius-Kaunas highway in Lithuania, SSR by collecting 120 liter (1 L/min for 120 min) samples on 2,4-dinitrophenylhydrazine-coated silica gel cartridges acidified with hydrochloric acid. The cartridges were preceded in the sampling system by potassium iodide-coated denuders to remove interfering ozone from the sample stream. Collected compounds were eluted from the cartridges with acetonitrile and analyzed using High Performance Liquid Chromatography with a UV (360 nm) detector, a Zorbax ODS analytical column, and a gradient water-acetonitrile mobile phase. Formaldehyde, acetaldehyde, and acetone were the most abundant oxygenated organic compounds observed, with lesser amounts of propionaldehyde, butyraldehyde, benzaldehyde, valeraldehyde, and tolualdehyde also generally observed. Formaldehyde concentrations ranged from 1.1 ppb (1.4 microgram/cu m) to 5.7 ppb (7.0 microgram/cu m), acetaldehyde from 1.2 ppb (2.2 microgram/cu m) to 5.0 ppb (9.0 microgram/cu m), and acetone from 2.3 ppb (5.4 microgram/cu m) to 6.8 ppm (16.2 microgram/cu m); the concentrations varied with wind direction and speed, and distance from the highway.