Introduction: Methanol is a commonly used organic solvent that, because of its toxicity, can cause metabolic acidosis, neurologic sequelae, and even death, when ingested. It is a constituent of many commercially available industrial solvents and of poorly adulterated alcoholic beverages. The management of acute human methanol intoxication needs methanol dosage. The aim of our study is to validate a method in the order to determinate the amount of blood methanol, using gas chromatography with flame ionization detection (FID), after a Headspace sampling. Methods: We used butanol as an internal standard. The validation procedure was performed according to the guidelines of the French Society of Analytical Toxicology and the French Committee of Accreditation (COFRAC; LABGTA04). Results: Our method is specific and linear at the range amount from 0g/L to 1 g/L. the coefficient of correlation was 0.99868. The intra- and inter-day precision and relative bias were less than 15 %. The limit of detection was 0.060 g/L. In the same conditions, limit of quantification was 0.09 g/L. The storage's and transport's samples were at +4