Objectives: In the developing countries with high mortality rates, poisoning is considered to be one of the most common causes of admission to emergency wards. Given the importance of registering data on poisoned patients, it is very important to have a complete poisoning Minimum Data Set (MDS). Therefore, the purpose of this study was to determine an MDS for poisoning registry in Iran. Methods: This applied and cross-sectional study was conducted through of Delphi technique in the poisoning ward of Imam Reza Hospital (northeastern Iran) in 2019. Literature reviews were initially carried out on such databases as PubMed, Web of Sciences, Scopus, and Embase. Then, Google search was done to retrieve poisoning forms and poisoning registry websites. Also, we considered International Classification of Diseases, 10th Revision coding guidelines of poisoning. Then, a questionnaire containing data elements of poisoning was developed. Results: In total, 558 data elements were developed during two rounds of Delphi technique. The MDS was divided into 10 categories including patient and communication data, encounter data, diagnostic data and medical history, exposure data, clinical data, treatment data, complications, paraclinical tests, biobank, and discharge data. Conclusions: Establishing an MDS as the first and most important step towards implementing poisoning registry can be the standard basis for collecting poisoned patient data. The data registered in the poisoning registry can be