The common peroneal nerve is one of the most frequent sites of neuropathy around the knee. Owing to its superficial course, it is highly vulnerable to both trauma and mechanical compression. High-frequency ultrasonography enables real-time, dynamic evaluation of the common peroneal nerve along its entire trajectory from the popliteal fossa to the exit from the peroneal tunnel. This article presents a stepwise, structured ultrasound protocol for the assessment of the common peroneal nerve in the peri-knee region. Supported by illustrative images and videos, the protocol is expected to facilitate practical applicability in daily practice and improve diagnostic accuracy. Furthermore, the guiding role of ultrasonography in interventional planning is highlighted.