Theophylline toxicity could be life-threatening due to refractory hypotension, severe cardiac arrhythmias or convulsions that may require extracorporeal removal of theophylline via hemodialysis.This study aimed to evaluate theophylline toxic manifestations to construct a predictive score to identify patients who are at risk and require hemodialysis.This study was a prospective study included patients with acute theophylline toxicity who were admitted to the Poison Control Center of Ain Shams University Hospitals during six months from the first of January 2019 to the end of June 2019.Collected data including sociodemographic, intoxication and clinical data. Outcome of patients and their needs for hemodialysis were also recorded. Routine investigations and theophylline levels were done for each patient in addition to ECG recordings.This study enrolled 175 theophylline intoxicated patients who met the inclusion criteria. All studied patients ingested theophylline intentionally, most of them were females with mean age of 22.11±8.65 years.The mean delayed time was 7.29±5.08 hours. Nausea and vomiting were the most common clinical manifestations, 4.6% of studied patients needed hemodialysis and all cases were discharged with no deaths. All cases were tachypneic, most of them were hypertensive, tachycardic and had abnormal ECG findings. In conclusion;Theophylline poisoning hemodialysis (TPH) score was constructed to find out the probability of patients need for hemodialysis. It consisted of nine important easily measured parameters which are theophylline and HCO3 levels, duration of hospital stay, pulse, respiratory rate, presence of hematemesis, seizures, agitation and abnormal ECG findings. Any case with 5 changes or more is critical and may need hemodialysis.