The behavioral effects of long-term exposure to a mixture of organic solvents were investigated in a comparison of the test results of 100 car painters with those of a reference group. The test battery included tests for intelligence, memory, psychomotor performances, and personality. In addition to the comparison of the mean results, two discriminant function analyses were made. In one, only the performance test variables were used, but in the other personality variables were also included. The results indicated impairments in psychological performances, as well as personality changes in the exposed group. Impairments in visual intelligence and verbal memory and a reduction of emotional reactivity were the central features of the adverse effects of solvent exposure, but the behavioral disturbances also involved several other functions, including performance on a verbal intelligence test. The possible role of the differences in the initial intelligence levels were controlled with a separate comparison of the test results of 33 pairs of exposed and nonexposed subjects who were matched for age and for their intelligence level, measured during the military service. The discriminant function analyses were based on the results of these matched subgroups and tested in the rest of the material. According to the results the sensitivity of the psychological test methods was high, but the specificity somewhat low, with regard to solvent exposure. The concentration of various solvents included in the exposure of car painters were low, the summated exposure corresponding corresponding to 32% of the Finnish threshold limit value. The possible role of a potentiating effect of the solvent in the development of behavioral disturbances is discussed.