The coexistence of systemic lupus erythematosus (SLE) and Wilson's disease (WD) is exceedingly rare, posing significant diagnostic challenges due to overlapping clinical presentations. Neurological and psychiatric manifestations commonly associated with WD can obscure or mimic symptoms of other systemic diseases, complicating accurate diagnosis and management. We report the case of a 17-year-old female diagnosed with WD and concurrent SLE, treated at Civil Hospital, Karachi, Pakistan. The patient initially presented with neuropsychiatric symptoms typical of WD, confirmed by diagnostic findings indicative of hepatic copper accumulation. She later developed significant proteinuria, hematuria, fever, and positive autoimmune serologies, raising suspicion of concurrent SLE. Despite therapeutic interventions, including methylprednisolone (1 mg), the patient's condition deteriorated, and she unfortunately succumbed to complications from a blood transfusion reaction. This case underscores the importance of heightened clinical vigilance when managing overlapping presentations of WD and systemic autoimmune disorders like SLE. Early recognition of WD-specific neurological and psychiatric symptoms is critical for timely diagnosis and intervention, potentially mitigating the risk of severe complications and poor outcomes.