The aim of the study was to carry out a toxicological chemical analysis of methanol in detectable quantities in the blood of patients with acute alcohol intoxication. Blood samples from 85 patients with acute alcohol intoxication were analysed for the presence of methanol. All patients with acute methanol intoxication were excluded from the study. The methods of gas chromatography with vapor-phase analysis (head-space) and flame ionization detection (FID) were used. The limit of detection (LOD=0.015 g/L) and the limit of quantification (LOQ=0.025 g/L) of methanol in whole blood were evaluated. In 30% of the cases, methanol was found in the blood in detectable quantities. The levels of methanol were on the average 5 to 6 times lower than the toxic methanol level (0200 g/L) and they were not due to natural metabolic processes (ingestion of fruit, fruit juices or vegetables). No reliable statistically linear correlation between the concentration of ethanol and methanol was found. Methanol subintoxications are major factors in alcohol intoxications, in which the quantity of the alcohol ingested is not as important as its quality. Chronic methanol subintoxication of people who often consume alcohol of poor quality is discussed.