Seventy-five years ago, Flagg suggested that postoperative vomiting may result from causes other than anaesthetics: "there are at least three kinds of vomiting", the first of which he attributed to anaesthetics such as ether, the second to reflex responses, that is pain or ovarian surgery, and the last to opioids, for example morphine [30]. Before this report, anaesthetics alone were thought to be responsible for most postoperative nausea and vomiting (PONV). Subsequent investigations unfolded a spectrum of non-anaesthetic factors in the pathogenesis of PONY including age, gender, motion sickness, body habitus, surgical site and postoperative feeding procedures. This review summarizes our current understanding of the roles of two categories of non-anaesthetic factors, patient and surgical factors, in the pathogenesis of PONY. Despite the recent advances in modern anaesthesia, only modest progress has been made in our understanding and treatment of PONY. Early studies reported incidences of PONY as high as 75-80 cYo after opioid premedication and prolonged ether anaesthesia [4,11,13,47,83,84]. In many of these reports, the patient population, premedication, anaesthetic and the surgical procedure were not controlled. In the second half of this century, however, these incidences have decreased by almost 50 % for various reasons [7,