Particular emphasis has been in recent years placed on the study of an integrating role of medicine in the prevention, early diagnosis, and treatment of diseases associated with the influence of environmental factors. Among nervous system diseases associated with the adverse influence of environmental factors, the parkinsonian syndrome has been the particular concern, which is due to its higher incidence rates and early disability in able-bodied persons. In this connection, the purpose of the study was to review the data available in the literature on the neurotoxicity of heavy metals and other environmental factors causing toxic parkinsonism. The mechanisms of development and the clinical manifestations of the parkinsonian syndrome were considered in occupational manganese poisonings, magnesium deficiency, and carbon monoxide intoxication. Profound assessment of the influence of environmental factors on certain population groups is possible only when hygienists, toxicologists, biochemists, immunologists, molecular geneticists, and clinicians combine their efforts.