Results of the clinical and neurophysiological examinations of 42 workers with operating history at the chemical plant exposed to vinyl chloride (VC) are presented. The purpose of research was the identification ofpeculiarities of clinical manifestations and disorders of the functional activity of the brain in workers at the vinyl chloride production, with taking into account the exposure toxic load (ETL). There were made clinical and electroencephalographic examinations with the detection of cognitive evoked potentials (CEP) and statistical analysis of results with the use of the Mann-Whitney U-test, Fisher’s F-test, calculation of Spearman’s correlation coefficient. The features in clinical picture of the pathology of the nervous system were detected in the form of asthenic disorders with cognitive impairment and autonomic dysfunction syndrome. There was established the increase in the cognitive impairment rate (p = 0.03), the decline in a-EEG activity (p = 0.01) and the worsening of indices of the amplitude (p = 0.011) and latency (p = 0,05) of CEP in extremely high level of ETL in comparison with same indices in the group with moderately high ETL. In the first group there was revealed a statistically significant exceedance of the frequency of hypertension - by 1.6 times, skin diseases - by 9 times, chronic subatrophic rhino-pharyngitis by 1.4 times in comparison with cases from the second group. In the group with moderately high level of ETL there was established the statistically significant inverse correlationship between the ETL and the index of P300 amplitude from the left side (r = -0.38, p = 0.019) and in the group with extremely high level ETL - between ETL and index of the β2 - rhythm (r = - 0.73, p = 0.0008).