Ethylene glycol (EG) is the most representative of the glycols. It is a compound used as painting and plastic solvent, as antifreeze, and in dyes and synthetic fibers. It may also appear as a wine pollutant. Due to these various uses and conditions, EG can produce intoxication in men and animals. The pathologic effects are due to its metabolism resulting in the formation of oxalic and glycolic acids which are eliminated through the kidney causing renal failure. The toxic effects on the nervous system are not well known. In some circumstances, convulsions may occur. To study the neurotoxic effects of EG, we used cultures of nerve cells from Wistar rat embryos which we exposed to EG in doses between 10(-4) M and 10(-8) M. The changes in neurons consisted of neuronal degeneration, decrease in number of AChE+ cells, and reactive cellular grouping. The median inhibitory concentration (IC50) was 2.06 x 10(-7) M.