Using quantitative neurohistological indices, a structure of the ventral posterior lateral nucleus of the thalamus has been studied in 10 cases from the collection of the Institute of Brain, Russian Academy of Medical Sciences. The sample included 6 men and 4 women aged from 19 to 55 years, right-handed, who died suddenly and did not suffer neurological or mental disorders. Density of satellite gliocytes and density of neurons surrounded by satellite gliocytes were determined. Variability of these characteristics was related to sex and hemisphere differences. The index of satellite glia in 0.001 mm(3) was more variable in the right side both in men and women. The index of neurons surrounded by satellite gliocytes was more variable in the left side in men and in the right side in women. The asymmetry of neuron-glia ratio in the ventral posterior lateral nucleus of the thalamus was not marked. But there was a trend to its predominance in the left hemisphere compared to the right one both in men and women. However, the characteristics studied were more variable in men while the asymmetry was more marked in women.