Abstract Background Poisoning is an important health care problem resulting in high morbidity and mortality rates especially in developing countries. About 4–40% of acute poisoned patients need intensive care units (ICU). Aim The aim of this study was to evaluate pattern of acute poisoning that required ICU admission, clinical characteristics and outcome of these patients in Tanta University Poison Control Center. Patients and methods All acute poisoned cases who admitted to ICU from the start of February 2017 to the end of July 2018 were included. Sociodemographic, characteristic clinical manifestations, laboratory investigations and outcomes were recorded. Results ICU admitted poisoned patients represented 6% of total poisoned patients. More than half of patients (54.4%) were in the age group between 18 and 40 years and 50.7% of patients were females. The highest percentage were from rural areas (87%) with suicidal intentions (76.8%). The main route of exposure was oral route (95%). Median delay time and hospitalization period were 3 h and 43 h, respectively. The most frequent poisons were aluminum phosphide (61.5%), organophosphates (11.5%) and digitalis (4.8%(. 32.7% of patients were hypotensive and 20.3% presented with undetected blood pressure. Mixed metabolic acidosis with respiratory alkalosis was the most frequent arterial blood gases abnormality (40%) and 51.4% of the studied patients died. Conclusion The most frequent three poisons that required ICU admission were aluminum phosphide, organophosphates and digitalis respectively. The alarming clinical presentations were hypotension, tachycardia, tachypnea and mixed arterial blood gas abnormality.