Gynaecologic oncology day surgery deals primarily with the diagnosis of endometrial, cervical, vulvar and vaginal tumors. Conscious sedation is an important technique used in gynaecologic oncology day surgery. It is often associated with regional anaesthesia. The goals of conscious sedation are to provide effective pain control with complete safety, reduction of the recovery time, of the infection risk and cost. Since the consequences of the immunosuppressive effects of the opiates and the surgical stress could lead to an increased susceptibility to post-operative infections and a possible lack of immunological defence in the cancer patients, we investigated the possibility of eliminating the administration of opiates during minor operations in gynaecologic oncology day surgery. In this study, 400 patients, aged between 35 and 77 years, underwent surgery using sedation at the day hospital annexed to the Gynaecology and Obstetrics Department of the 2nd University of Naples, Italy. The patients were randomized into two equal study groups, according to a computer-generated randomised list. All patients were seen by the consultant anaesthetist three days before surgery. In all cases, during surgery, we monitored the main vital parameters such as ECG, HR and RR, BT, BP and SO. The drugs commonly used were: opioids, hypnotics and benzodiazepines, associated or not, with local anaesthetics. By using these drugs, pain and anxiety were reduced, sedation and amnesia were accomplished. In our experience, conscious sedation seems to be the best choice in gynaecologic oncology day surgery because it presents low toxicity, is short acting and readily reversible, has a low cost and, finally, because it is more comfortable for the patients. Moreover, it is possible to eliminate the administration of opiates during conscious sedation for less invasive surgical procedures.