Treatment options for patients with aggressive chronic inflammatory demyelinating neuropathy are limited and include the anti-CD20 antibody rituximab and the immunosuppressive regime cyclophosphamide. We aimed to investigate retrospectively the efficacy of bortezomib, a proteasome inhibitor tackling highly metabolically active cell types such as plasma cells, in a case series of 10 treatment refractory CIDP patients. All patients reported showed a deterioration of the clinical CIDP scores under first-line treatment or escalating treatment with cyclophosphamide or rituximab. One or two cycles of bortezomib treatment (each cycle with 1.3 mg/m² administered s.c. on days 1, 4, 8, and 11) stabilized the majority of the patients (n = 6) during treatment and even improved clinical and electrophysiological parameters of four patients up to 1 year later. No relevant side-effects were reported. Two patients received autologous peripheral blood stem cell transplantation after bortezomib, which led to fatal infections. We conclude that bortezomib could be an attractive escalating treatment option with a good side-effect profile for patients with treatment refractory CIDP.