The effect of tail pinch on acetylcholine release in the striatum of freely moving rats was studied by microdialysis immediately after inhalation exposure to toluene (2000 ppm, 2 h) or exposure to air only. It has recently been found that toluene increases extracellular dopamine levels while decreasing acetylcholine release, and that dopamine uptake inhibition increases both extracellular dopamine levels and acetylcholine release, suggesting that toluene decreases acetylcholine release by a dopamine-independent mechanism. The present experiment was an attempt to study if a behaviourally induced increase of extracellular dopamine differs from that induced by toluene in affecting striatal acetylcholine release. Acetylcholine released increased during tailpinch in the unexposed as well as the toluene exposed group. No difference between the two groups in the acetylcholine release response to tailpinch was demonstrated. The result supports the conclusion that acute toluene exposure decreases acetylcholine release via a dopamine independent mechanism, and suggests that toluene exposure does not affect the striatal acetylcholine response to an acute stressful stimulus.