With respect to epidemiology of carbon monoxide poisonings, the diagnostic management of poisonings caused by this xenobiotic is among the fundamental objectives of forensic toxicology. In forensic practice, to determine carbon monoxide, colorimetric and spectrophotometric methods, as well as gas chromatography are used. Based on literature data and their own experience, the authors discuss analytical methods universally applied in determinations of carbon monoxide in postmortem blood. The advantages and disadvantages, as well as the cause of errors resulting from the specificity of the examined material (postmortem blood) are indicated.