The effect of inhalation exposure to toluene (3700 mg/m³, 1000 ppm, 21 h/day, 5 days/week, during 4 weeks) on male Sprague-Dawley rats was tested. A wide range of test situations was used, including an operant test with baseline performance and extinction, motor coordination, and exploratory activity. All tests were made 11 to 35 days after the end of the exposure. The results indicate that toluene exposure causes a long-lasting impairment on the extinction process and reduction in the variability of the baseline response in the operant behavior situation. Toluene also had an effect on the water regulation.