Tetrahydrocannabinol (Δ9-THC) is a psychoactive substance that is found in Cannabis sativa L., which has been globally linked with acute toxicity cases. Finding the best biological sample for quick and accurate THC detection is essential for medical and forensic oversight. This study aimed to evaluate the most precise sample type for rapidly and accurately determining cannabis levels. We conducted a case-control study at Benha Poisoning Control Unit. Benha University Hospital, from December 1, 2023, to April 30, 2024. One hundred sixty-eight participants were recruited, comprising 84 with acute cannabis toxicity and 84 controls who matched in age and sex. Sociodemographic information, vital signs, clinical symptoms (neurological, gastrointestinal, and respiratory), and THC levels in blood, urine, and oral fluid using immunoassay (cutoff: 50 ng/mL) were all evaluated. The majority of cases were male (71.4%), aged 19-59; 52.4% were inhaled, while 83.3% were intentionally exposed. Common symptoms included tachycardia (47.5% when compared to controls), anxiety (40.8%), decreased consciousness (59.5%), vomiting (23.8%) and nausea (11.9%). THC levels (ng/mL) after 30 hours of exposure varied from 66 to 90 (blood), 59 to 77 (urine), and 400 to 700 (oral fluid/saliva). Three hours for blood and urine Cmax, and five to nine hours for oral fluid. The maximum AUC (0–9h: 3977.08 mcg/mL.hr) and a positive correlation with blood (r=0.9, p