This paper reports three rare cases of accidental sodium nitrite poisoning, including one fatality, caused by the consumption of aspic purchased from a private vendor. Clinical symptoms included cyanosis, hypotension, and respiratory distress, with methemoglobin (MetHb) levels ranging from 5 % to 41.7 %. Toxicological analysis, performed using gas chromatography coupled with a mass spectrometry in the negative chemical ionization mode (GC-NCI-MS), revealed nitrite concentrations in blood samples ranging from 4.2 to 44 µg/mL and nitrate concentrations from 36 to 256 µg/mL. Urine analysis in the fatal case showed nitrite levels exceeding 100 µg/mL. The patients received symptomatic and supportive care, and methylene blue administration was considered in cases with elevated MetHb levels. One patient died despite aggressive resuscitation efforts, highlighting the rapid progression of severe nitrite poisoning. Postmortem findings included characteristic chocolate-brown discoloration of the blood and brown organ tissues, indicative of methemoglobinemia. This study emphasizes the clinical and toxicological importance of early diagnosis and intervention in nitrite poisoning and discusses the medico-legal implications of such cases, including the forensic challenges in interpreting postmortem toxicology results.