Statin-induced necrotizing autoimmune myopathy (SINAM) is a rare but critical complication of statin therapy that leads to progressive muscle weakness. The complicated mechanisms underlying it make both diagnosis and treatment difficult. It is essential to recognize the condition early, especially in people who have had muscle problems treated with statins in the past. A 73-year-old woman arrived at the emergency department due to increasingly severe symmetrical muscle weakness accompanied by markedly elevated liver enzymes, creatine kinase (CK), and cardiac troponins. Although an acute cardiac event was ruled out, further tests indicated progressive myositis, necessitating hospitalization. A muscle biopsy subsequently confirmed myopathy with complement deposition, and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibodies were detected. With treatment that included corticosteroids, intravenous immunoglobulin, and rehabilitation, the patient showed remarkable improvement. This case undeniably highlights the critical importance of early detection of SINAM and intervention and emphasizes the absolute need for further research into causes and treatment strategies.