Objectives Injuries to the ankle ligaments are some of the most common musculoskeletal sports injuries. Ankle magnetic resonance imaging (MRI) is the standard diagnostic procedure in today's practice, but its reliability and validity remain controversial. The aim of this study was to explore the approach for patients with negative ankle MRI who continue to have symptoms of ankle instability despite conservative therapy. Methods A total of eight patients who were 14 years or older with negative ankle MRI who continue to have symptoms of ankle instability despite conservative therapy were admitted to our institution from January 1, 2015 to December 31, 2021. Results Eight patients with a mean age of 36, and a mean body mass index (BMI) of 37.7. All patients presented with ankle pain, locking, and giving way in variable severity. All the patients had a radiograph followed by an ankle MRI, which showed normal alignment of ankle joints without abnormality. Initially, all patients were treated conservatively but did not show any improvement. After that, they underwent an operation of lateral ankle ligament reconstruction by modified Brostrom technique, followed by casting and physiotherapy. The symptoms of ankle instability resolved in all patients. The ankle pain resolved completely in six patients, improved in one patient, and did not improve in one patient. Conclusion Based on our results, we advocate reconstruction surgery by modified Brostrom technique for ligament repair in patients with clinical evidence of chronic ankle instability who have failed a trial of conservative management, even in the context of a normal ankle MRI.