In the paper the authors have presented a possible use of formic acid detection in biological specimens in the diagnosis of methanol poisonings. Formic acid was determined as a volatile methyl formate ester by the gas chromatographic head-space method. Based on opinions relating to methanol poisonings, formulated in the Forensic Medicine Department, Silesian School of Medicine, Katowice a potential application of the method mentioned above to forensic medicine was shown, especially in cases of late deaths after methanol intoxication and also a possibility of its use in clinical evaluation of the poisoning phase as well as monitoring the course of treatment.