BACKGROUND AND AIMS: The effect in smokers of nicotine withdrawal following surgery may contribute to the development of postoperative delirium. Nicotine is known to increase myocardial oxygen demand, coronary vasoconstriction, and may cause platelet activation leading to thrombosis. All of this can negatively impact postoperative recovery. The aim of this study was to determine whether nicotine replacement therapy can overweigh its negative effects, reduce the incidence of delirium, reduce the need for sedatives/analgesics, and/or shorten the duration of artificial pulmonary ventilation. METHODS: This prospective randomized single-blind study was performed in a 21-bed ICU. Fifty-two patients (26 intervention/ 26 control) met the inclusion criteria. Patients in the intervention group received a 21mg nicotine patch daily until discharged from the ICU (up to 7 days), patients in the control group received a placebo patch. The incidence of delirium was monitored with the CAM-ICU test. Sedatives/analgesics used in the ICU, and the duration of both artificial ventilation as well as total ICU stay were recorded for both groups. RESULTS: Nicotine replacement in smokers did not reduce the incidence of delirium in patients who had undergone surgery. Neither did it statistically significantly affect the length of hospitalization, sedation, analgesia, or vasopressors. CONCLUSION: This study did not confirm the effect of nicotine replacement therapy in reducing the incidence of delirium, it did not shorten the total duration of ICU stay or artificial ventilation and there was no reduced sedation requirement. We therefore saw no beneficial effect in patients receiving nicotine replacement therapy following elective surgery.