Background <p>Nalbuphine is synthetic agonist-antagonist opioid compound. Allergic reactions to nalbuphine hydrochloride are exceedingly rare. We present a case of hypersensitivity reaction to nalbuphine in a pre-adolescent patient.</p> Case presentation <p>A male patient, aged 11 years, underwent general anesthesia for the correction of congenital strephexopodia. Nalbuphine hydrochloride was administered as part of the postoperative analgesia regimen. However, the patient subsequently developed an allergic reaction characterized by pulmonary edema, wheezing, tachycardia and cutaneous rash. Prompt initiation of anti-allergic therapy resulted in significant clinical improvement. The patient was subsequently transferred to the general ward following complete resolution of symptoms.</p> Conclusions <p>This case report highlights a hypersensitivity reaction to nalbuphine in pre-adolescent patient, manifesting with both cutaneous and respiratory symptoms. To improve the safety profile of nalbuphine in pre-adolescent populations, further research is necessary to elucidate the underlying mechanisms of such adverse reactions.</p>