Objectives Chronic inflammatory axonal polyneuropathy (CIAP) is defined on the basis of the clinical, electrophysiological and nerve biopsy findings and therapeutic responses of € immunotherapy responding chronic axonal polyneuropathy (IR-CAP)'. Methods The diagnosis of IR-CAP was made when all of three of the following mandatory criterion were met: (1) acquired, chronic progressive or relapsing symmetrical or asymmetrical polyneuropathy with duration of progression >2 months; (2) electrophysiological evidence of axonal neuropathy in at least two nerves without any evidence of € strict criteria of demyelination'; and (3) definite responsiveness to immunotherapy. Results Thirty-three patients with IR-CAP showed similar clinical features of chronic inflammatory demyelinating polyneuropathy (CIDP) except € motor neuropathy subtype'. High spinal fluid protein was found in 27/32 (78%) cases. € Inflammatory axonal neuropathy' was proven in 14 (45%) of 31 sural nerve biopsies. Discussions IR-CAP could well be € axonal CIDP' in view of clinical similarity, but not proven as yet. Thus, IR-CAP is best described as CIAP, a distinct entity that deserves its recognition in view of responsiveness to immunotherapy. Conclusion Diagnosis of CIAP can be made by additional documentation of € inflammation' by high spinal fluid protein or nerve biopsy in addition to the first two diagnostic criteria of IR-CAP.