OBJECTIVE The follow-up and monitoring of response to immunomodulatory therapy in patients with chronic inflammatory demyelinating polyneuropathy are still challenging. Various outcome measures have been proposed in recent years, and some are now frequently used in daily clinical practice; however, reliable biomarkers for the disease activity and treatment response are lacking. METHODS Cross-sectional nerve area of the bilateral vagus, fifth and the sixth cervical spinal, median, ulnar, tibial, peroneal, and sural nerves were measured at 2 time points with an interval of 6 months using nerve ultrasound. The results were used to calculate the ultrasound pattern sumscore (UPSS). The correlation between UPSS change (ΔUPSS) and changes in functional and nerve conduction studies measures over the study period were assessed. RESULTS Sixteen patients completed this prospective, observational study. General linear model showed that ΔUPSS is significantly associated with ΔMedical Research Council sumscore (β = -0.72, P = 0.003), Δhandgrip strength (β = -0.57, P = 0.014), ΔRasch-built overall disability scale (β = -0.57, P = 0.010), and Δoverall neuropathy limitations scale (β = 0.75, P < 0.001), after adjustment of confounding variables. Nevertheless, ΔUPSS was not correlated with other clinical measures, including Δpinch power, Δ9-hole peg test, Δ10-m walking test, and Δnerve conduction study sumscore ( P values > 0.05). CONCLUSIONS Nerve ultrasound might be an efficient method for monitoring the functional status of patients with chronic inflammatory demyelinating polyneuropathy over time because the alterations in its scores could significantly reflect clinical changes.