Abstract -------- **PURPOSE:** Conditions precipitating delirium in older people are often multiple and a significant number are frequently missed at their initial assessment. We decided to develop a checklist to help clinicians to systematically screen for the most frequent and important acute causes of delirium in this population. **METHODS/** Three investigators, based in previous studies, drafted three possible checklist base models, comprising 18 to 29 items. A panel of twelve experts voted to choose one of the three models, then followed a modified Delphi consensus method to review each item and further develop the checklist and its organization. The consensus checklist was finally tested in a small group of patients. The target population was older patients with delirium arriving to the emergency department or to a medical hospital ward. **RESULTS:** The longest of the three drafts was unanimously chosen by the panel. After three rounds, a consensus was reached and a final checklist agreed. It is composed by 27 items organized in 5 groups of causes: infection, hydro-electrolytic disturbances, drugs, acute neurological conditions, and other acute diseases. A pilot study conducted by 15 physicians in 21 consecutive patients showed that the checklist was easy to complete, quick (mean 4 minutes) and most clinicians though it helped them through the initial diagnostic work. **CONCLUSIONS:** We have developed and pilot tested a checklist for screening for the most frequent and important causes of delirium in older patients, aimed to facilitate early recognition and treatment of the multiple causes that often coexists in this population.