Introduction A silent revolution is under way in anesthesiology, one that will have a lasting impact on our patients and our practice. I refer to the research potential of ‘big data’ in anesthesiology, driven by the rapid uptake of Information Age technology in our offices, clinics and hospitals. Electronic healthcare records (EHRs) are changing the way we care for patients, the way we document and bill, and how we understand our practice. In the long run they will do much more: they will provide a fundamental ability to link clinical decision-making in the operating room with patient outcomes in a way that lets us learn from every patient encounter. This article will provide a brief overview of existing large datasets describing anesthesia patients, procedures and outcomes. I will review their current contents and structure, their future development, and their long-term potential for comparative effectiveness and health services delivery research. Existing Anesthesia...