Neuropathic pain is caused by an insult to the nervous system and accounts for 25-50% of all pain clinic visits. Excluding low back pain, diabetic peripheral neuropathy is the most common neuropathic pain syndrome with an estimated prevalence of 600,000 cases in the United States. There are only 5 medications approved by the FDA for the treatment of neuropathic pain with only 2 out of the 5 approved for the treatment of diabetic peripheral neuropathy. Currently, there is a desperate need for more therapeutic agents for the treatment of neuropathic pain. We propose to use painful diabetic peripheral neuropathy (DPN) patients to study the efficacy of inhaled cannabis on neuropathic pain. We will enroll 20 subjects with each subject acting as their own control; receiving both placebo and three doses of inhaled aerosolized cannabis (low, medium, and high) in random order each separated by at least two weeks. Subjects will be assessed for reduction in pain, changes in normal sensation, changes in cognition, and effects of cannabis on experimentally induced pain.