Aim: To describe the registry design of the Osaka Emergency Information Research Intelligent Operation Network system (ORION) and its profile of hospital information, patient and emergency medical service characteristics, and in-hospital outcomes among all patients transported to critical care centers and emergency hospitals in Osaka Prefecture, Japan. Methods: The Osaka Prefecture Government has developed and introduced an information system for emergency patients (the ORION system) that uses a smartphone application (app) for hospital selection by on-scene emergency medical service personnel and has been accumulating all ambulance records. Since January 2015, medical institutions have obtained information on the diagnosis and outcome of patients transported to medical institutions, and the ORION system merged these data with ambulance records including smartphone app data. Results: From January 2015 to December 2016, 753,301 eligible patients were registered. The mean age was 58.7 years, and 51.5% of patients were male. After hospital arrival, 39.7% were hospitalized, 58.2% were discharged from hospital, 1.1% changed hospital, and 1.0% died. The most common diagnoses were injury, poisoning, and certain other consequences of external causes. Among the hospitalized patients, 29.2% were continuously hospitalized, 59.0% discharged, 5.2% changed hospital, and 5.8% were dead at 21 days after hospitalization. The most common confirmed diagnosis was diseases of the circulatory system. Conclusion: Using the ORION system developed and operated by Osaka Prefecture since January 2015, we described the epidemiological data of all emergency patients transported to emergency hospitals. Analysis using the ORION database in the future could lead to improvements in the emergency transport system and patient outcomes.