Lindane distribution in brain areas after oral (30 mg/kg) and i.v.(0.3 mg/kg) administration was studied using autoradiography-imaging analysis and dissection-liquid scintillation counting techniques. Both experimental approaches gave similar results. An heterogeneous distribution of lindane-label in brain regions was observed. Radiolabel concentration in white matter was higher than in grey matter and the concentration ratio was time increasing. Higher concentrations of lindane-label were found in thalamus, mid-brain and pons-medulla at different times after administration when compared to the whole brain mean value. Pretreatment with 300 mg/kg of the alpha-HCH isomer did not induce significant modification in the pattern of lindane radioactivity distribution in brain. Lindane affinity for white matter and myelinated structures could be related to its lipophilic behaviour and is not in disagreement with the current proposed mechanism of action for this xenobiotic.