INTRODUCTION AND IMPORTANCE: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are the severe adverse drug reactions following drugs like carbamazepine, allopurinol, and infections. Here we present A 32-year-old woman developed SJS/TEN after 7 days of carbamazepine therapy, highlighting the importance of recognizing this risk, particularly in HLA-B*1502 allele carriers. CASE PRESENTATION: A 32-year-old female developed fever, vomiting, and mucocutaneous blisters 7 days after starting carbamazepine. Lesions spread from the face to the chest, abdomen, and extremities, with throat discomfort and eye discharge. History included prior dizziness episodes. Examination revealed denuded skin, positive Nikolsky's sign, and HLA-B*1502 allele positivity. Treatment comprised ceasing carbamazepine, fluid administration, and steroids. DISCUSSION: SJS/TEN manifest with distinct symptoms and often emerge within weeks of drug exposure. Carbamazepine, a frequent trigger, poses higher risks for HLA-B1502 allele carriers. Timely identification and intervention are essential to reduce mortality rates (10-40%). Treatment involves corticosteroids and supportive measures, with pre-carbamazepine HLA-B1502 screening advised, despite potential accessibility constraints. CONCLUSION: This case underscores the necessity of recognizing carbamazepine-induced SJS/TEN risk, particularly in HLA-B*1502 carriers. Despite screening challenges, early intervention involving multidisciplinary specialists is essential for favorable outcomes. Increased awareness and proactive measures are vital in preventing and managing these severe reactions.