To evaluate the efficacy and safety of pregabalin administered twice a day compared to placebo in reducing pain in subjects with painful diabetic peripheral neuropathy.

Inclusion Criteria:

• Males or females at least 18 years of age, of any ethnic origin
• Type 1 or 2 diabetes mellitus
• Pain score greater than or equal to 4 on the 11-point numeric pain rating scale

Exclusion Criteria:

• Neurologic disorders unrelated to diabetic neuropathy that may confuse or confound the assessment of neuropathic pain.
• Presence of severe pain associated with conditions other than diabetic peripheral neuropathy, that could confound the assessment or self-evaluation of pain due to DPN.