Abstract Background and aim: The aim of this prospective, observational study was to evaluate the potential benefit of nalbuphine in paediatric adenotonsillectomy in comparison to alfentanil in the terms of the emergence delirium and other procedural adverse events. Methods: Monitored adverse events were tachycardia, dyspnoea, hypotension, hypertension and emergence agitation according to the adapted Watcha scale. All eligible patients were given oral premedication and general anaesthesia was induced using inhalational or intravenous route. Patients were given nalbuphine (0.1-0.2 mg.kg-1) or alfentanil (10-15 ug.kg-1) and had all requested data recorded in the study form (age, study group, metamizole usage, body weight, total dose of nalbuphine or alfentanil, ASA, studied parameters). Results: Total of 122 patients were enrolled for this study, 8 patients were excluded because of incomplete study form. This resulted in study population of 114 patients. All patients were ASA I–II. No differences in age or body weight were observed. Emergence agitation was significantly (p=0.024) more frequent in the Alfentanil group (39.66%) than in Nalbuphine group (19.64%). Tachycardia was significantly more frequent in younger patients. Dyspnoea was significantly dose-dependent and more frequent in lower dosages (p=0.045). Hypertension was more frequent in patients with higher grade of agitation, but statistically significant only in the Alfentanil group (p=0.044). Conclusion: Nalbuphine in the setting of paediatric adenotonsillectomy makes a good alternative to short acting opioid and postoperative analgesia using NSAID or other nonopioid analgesics. Our results show that nalbuphine provides less emergence agitation and therefore provides a patient better early postoperative outcome.