RATIONALE: Longitudinal extensive transverse myelitis (LETM) is a rare form of acute transverse myelitis occurring in 1%-2% of systemic lupus erythematosus (SLE) cases. It often leads to severe sensory and motor deficits with bowel and bladder dysfunction. Reports of complete functional recovery in SLE-related LETM are limited, and the significance of early and aggressive intervention remains insufficiently understood. PATIENT CONCERNS: A 31-year-old female with prediabetes and iron deficiency anemia was hospitalized for hematochezia and diarrhea. On the third day of admission, she experienced sudden bilateral lower extremity weakness resulting in a fall. DIAGNOSES: Further evaluation revealed findings consistent with SLE-related LETM, confirmed through clinical, laboratory, and imaging assessments. INTERVENTIONS: The patient received aggressive medical management for SLE-LETM, followed by a multidisciplinary rehabilitation program. Over 1 year, she completed acute inpatient rehabilitation and continued outpatient physical, occupational, and aquatic therapies. She also used an ankle-foot orthosis, a cane, and a front-wheeled walker as needed during her recovery. OUTCOMES: Over the course of 1 year, the patient demonstrated marked progressive improvement, ultimately achieving functional ambulation with assistive devices and a Berg Balance Scale score of 48/56. LESSONS: This case underscores the importance of prompt diagnosis, aggressive medical therapy, and early multidisciplinary rehabilitation in optimizing recovery in SLE-LETM. Although this condition is often associated with poor outcomes, significant functional recovery is achievable with timely and intensive management. Further studies are needed to clarify the role of early rehabilitation in long-term outcomes.