In order to establish a diagnostic criteria for diabetic polyneuropathy (DP) for daily practice, usefulness of the abbreviated diagnostic criteria proposed by Diabetic Neuropathy Study Group in Japan was examined in 131 diabetic patients in admission and outpatient clinic. The prerequisite condition includes: (1) diagnosed as diabetes and (2) other neuropathies than diabetic neuropathy can be excluded. The criteria should meet any of the following three items: (1) sensory symptoms considered to be due to DP, (2) bilaterally decreased or absent ankle reflex and (3) decreased vibratory sensation in bilateral medial malleoli. Using this criteria, sensitivity (68%) and specificity (74%) were obtained by evaluating nerve conduction study as gold standard, suggesting usefulness of the criteria for diagnosis of DP especially for daily practice. Staging of DP is now sought to establish the consensus for the specific therapy for its stage. Thirty-one diabetic patients in admission was evaluated to examine usefulness of the newly devised staging system of DP. Staging was almost consistent between the new staging system and Dyck's staging (gold standard) and nerve function deteriorated with increasing stage, suggesting that usefulness and rationale of this staging system is well substantiated.