A prospective study was performed on 28 patients who underwent surgery for tendon disorders around the ankle. Preoperatively, all patients had real-time, high resolution ultrasonography performed with a 7.5 or 10 mHz transducer. Twenty of these patients also had a preoperative magnetic resonance imaging (MRI) examination of the ankle. A total of 54 tendons were inspected intraoperatively, revealing a total of 24 intrasubstance or complete tendon tears. These surgical findings were compared with the ultrasound and MRI findings, from which the sensitivity, specificity, and accuracy were calculated for both modalities. Ultrasound produced results with a sensitivity measurement of 100%, specificity of 89.9%, and accuracy of 94.4%. MRI produced results with a sensitivity measurement of 23.4%, specificity of 100%, and accuracy of 65.75%. Ultrasound results were more sensitive and accurate than MRI in the detection of ankle tendon tears in our study.