Phosphine, a lethal gas, forms upon contact of Aluminium or Zinc Phosphide with acid or water. When phosphide reacts with gastric acid, the resulting gas quickly enters the bloodstream and causes acute damage to internal organs leading to cardiac arrest and heart failure. Two cases of suspected poisoning, involving one man and one woman, were received in the author's laboratory for toxicological analysis. Presumptive testing of phosphine using silver nitrate strips was performed on gastric contents and gastric lavage. We conducted confirmation and quantification of phosphine in gastric lavage, blood, urine, gastric contents, and liver using a gas chromatography-nitrogen phosphorous detector equipped with a PLOT column. To estimate the phosphine concentration in the submitted samples, we prepared calibrators (ranging from 10 to 500ng/mL) through serial dilution. All analyzed specimens from both cases were found positive for phosphine. Gastric lavage, blood, gastric contents, and liver were found to contain 264ng/mL, 21ng/mL, 268ng/mL, and 30ng/g respectively. Traces of phosphine were also detected in urine sample. Detection of phosphine in gastric contents and gastric lavage in significant amount supports oral intake of phosphine by the victims. Furthermore, presence of phosphine in blood and liver indicates its systemic distribution while urine detection of phosphine serves as evidence of one of its excretion mechanisms.