Background: Painful diabetic neuropathy (PDN) is a frequent complication of diabetes mellitus. Current treatment recommendations are based on short-term trials, generally of duration ≤3 months. Limited data are available on the long-term outcomes of this chronic disease. This study aims to determine the long-term clinical effectiveness of the management of chronic PDN at tertiary pain centres. Methods: From a prospective observational cohort study of patients with chronic neuropathic non-cancer pain recruited from seven Canadian tertiary pain centres, 43 patients diagnosed with PDN were identified for analysis. Data were collected according to Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) guidelines including Brief Pain Inventory (BPI). Results: At 12-month follow-up, 37.2% of 43 patients achieved pain reduction of ≥30%, 51.2% achieved functional improvement with a reduction of ≥1 on the Pain Interference Scale (0-10, BPI), and 30.2% (95% CI: 17.2% to 46.1%) had achieved both these measures. Symptom management included at least 2 medication classes in 55.3%, and 3 medications classes (opioids, antidepressants, anticonvulsants) in 25.5%. Conclusions: A sizable minority of patients being managed for PDN in a tertiary care setting achieve meaningful improvement. Polypharmacy, including analgesic antidepressants, anticonvulsants and opioids, is often necessary to attain symptom management.