1. The effects of Adafenoxate (Adf), meclofenoxate (Mf) and citicholine (CCh) administered at a daily dose of 100 mg/kg for 7 days on the levels of noradrenaline (NA), dopamine (DA) and serotonin (5-HT) in the frontal cerebral cortex, striatum, hippocampus and hypothalamus of rats were studied. 2. Adafenoxate increased the NA level in the striatum and decreased it in the hypothalamus; it increased the DA level in the cerebral cortex and hypothalamus and decreased it in the striatum; it increased the 5-HT level in the cerebral cortex and decreased it in the hippocampus. 3. Meclofenoxate decreased the NA level in the cerebral cortex and hypothalamus; it increased the DA level in the hippocampus and hypothalamus and the 5-HT level in the cerebral cortex, striatum, hippocampus and hypothalamus. 4. Citicholine increased the NA level in the cerebral cortex and hypothalamus; it increased the DA level in the striatum and the 5-HT level in the cerebral cortex, striatum and hippocampus. 5. An attempt is made to explain some similarities and differences in the behavioral effects of the drugs tested (and those observed in other studies) by the changes they induce in brain biogenic monoamines.