Rationale:Acute compartment syndrome is a highly aggressive condition, which needs rapid diagnosis and surgical emergency. Most cases are caused by trauma, fractures, surgeries, or vascular injury, while other causes are easily misdiagnosed.Patients concerns:A 29-year-old female, with a medical history of an insect bite on the left calf but not recent trauma, was admitted to the hospital due to the swelling and pain around the bite area.Diagnoses:Acute compartment syndrome of the lower leg.Interventions:After admission, she developed septic shock symptoms, given intravenous antibiotics treatments. However, the condition worsened with increasing pain, loss of sensation, tense swelling, and severe pain to any stretch of the tissues. Thus the patient received fasciotomy followed by repeat and thorough debridement. After the wounds healed completely, systematic rehabilitation was performed for three weeks.Outcomes:After three months of follow-up, the patient is able to walk, and moves up and down the stairs, independently.Lessons:Our case highlights the possibility of acute compartment syndrome caused by insect bites when the patient presents with the signs of the condition, and the importance of earlier rehabilitation interventions to improve the functional outcome post operation.