One-third of all hospital-regulated medical waste (RMW) comes from the operating room (OR), and it considerably consists of disposable packaging and wrapping materials for the sterilization of surgical instruments. This study sought to identify the amount and type of waste produced by ORs in order to reduce the RMW so as to achieve environmentally-friendly waste management in the OR. We performed an initial waste segregation of 4 total knee replacement arthroplasties (TKRAs) and 1 total hip replacement arthroplasty, and later of 1 extra TKRA, 1 laparoscopic anterior resection of the colon, and 1 pelviscopy (with radical vaginal hysterectomy), performed at our OR. The total mass of non-regulated medical waste (non-RMW) and blue wrap amounted to 30.5 kg (24.9%), and that of RMW to 92.1 kg (75.1%). In the course of the study, we noted that the non-RMW included recyclables, such as papers, plastics, cardboards, and various wrapping materials. The study showed that a reduction in RMW generation can be achieved through the systematic segregation of OR waste.