BackgroundLow back pain is extremely common and usually a minor self-limiting condition. Rarely, however, it is a harbinger of serious medical illness. Paraspinal compartment syndrome is a rare condition, but its timely recognition is important to allow adequate treatment. Case ReportA 16-year-old boy presented to the Emergency Department (ED) with severe low back pain, necessitating intravenous opioids. Laboratory results showed severe rhabdomyolysis. Magnetic resonance imaging of the lumbar spine showed diffuse edema and swelling in the paraspinal muscles. Aggressive fluid therapy was started but despite narcotic analgesia the pain persisted and creatine kinase (CK) levels increased. Compartment pressures of the erector spinae were found to be increased. The decision was made to proceed with bilateral paraspinal fasciotomies. Postoperatively, the patient noted immediate pain relief with rapid decrease of CK level. The patient is pain free and resumed running and swimming 3 months after admission in the ED. Why Should an Emergency Physician Be Aware of This?Although paraspinal compartment syndrome is a rare condition, its recognition is of paramount importance to allow adequate surgical treatment, preventing muscle necrosis. Although back pain most often has a benign course, a careful history and physical examination in patients presenting with low back pain allows determination of “red flags.” Mandatory further diagnostic tests can identify underlying serious illness.