The purpose of our study was to examine the preoperative clinical factors and magnetic resonance imaging (MRI) findings associated with peroneal pathology in chronic lateral ankle instability patients, as well as the clinical factors associated with peroneal lesions being detected on MRI. Peroneal pathology was determined from intraoperative findings. Patients with/without peroneal pathology were compared regarding their preoperative clinical findings. MRI reports were examined to determine the sensitivity of detecting peroneal pathologies. Clinical factors were compared between patients (N = 238) with undetected and detected peroneal lesions on MRI. Conservative treatment, preoperative physical therapy, and lack of a traumatic inciting event were associated with peroneal pathology. MRI had a sensitivity of 61.11% for detecting peroneal pathology. No clinical factors were significantly different between “detected” and “undetected” cases. Certain historical factors were associated with peroneal pathology in patients with chronic lateral ankle instability, and MRI had a high false-negative rate. Surgeons should exercise caution when ruling out peroneal pathology based on preoperative physical examination or MRI.