Alcohol is one of the oldest known substances used for human enjoyment throughout history. Due to alcohol abuse it causes acute and chronic poisonings and is by far the most used psychoactive substance in the world. Post-mortem analysis of body fluids for the presence of alcohol is one of the most requested searches in forensic medicine and toxicology due to alcohol involvement in forensic and legal disputes in cases such as traffic fatal accidents, murders, suicides and other violent deaths. Spotting the differences in ethanol concentrations in some body fluids postmortem, the research of the subsequent findings, and the clarification of why and how they occur is the purpose of this diploma thesis. Twenty five patients who died from various causes in the period from September 2013 through April 2015, have been included in an retrospective analysis of data acquired from the Institute for Forensic Medicine, School of Medicine in Rijeka. The method used to measure alcohol concentration in body fluids in this study was gas chromatography. Body fluids analysed in this study included urine, blood from the head, and several preliminary samples of vitreous humour which can serve as an alternate pattern for determing the degree of alcohol intoxication. Higher blood levels of alcohol to urine ratio are possible only during the absorption stage. Most of the respondents in this survey were in the elimination stage.