The subtle clinical and radiographic findings of an unstable Lisfranc ligament injury can be easily misdiagnosed as a stable midfoot sprain. Appropriate treatment ranges from conservative management to surgery, depending on the extent of ligament disrup- tion and subsequent joint instability. Initial evaluation with non-weight bearing radiographs is often normal in unstable injuries. The results of missed or inappropriately treated Lisfranc injuries are poor. Chronic joint instability can lead to persistent pain, degenera- tive joint disease, and decreased functional capacity. Inability to return to previous levels of activity may result from painful midfoot arthritis. It is important to have a high index of suspicion for unstable Lisfranc injuries in patients who present with midfoot pain after low-energy injuries. Stress radiographs and magnetic resonance imaging can help differentiate between stable and unstable ligament sprains. Referral to an orthopedic surgeon is appropriate for injuries that result in joint diastasis. Long-term outcomes are optimized by early anatomic reduction.