Inclusion Criteria:

• Volunteers 40-65 years of age.
• Meet the Classification Criteria of the American College of Rheumatology for osteoarthritis of the right knee for at least the past 3 months, as determined by the referring physician.
• If patients have a diagnosis of bilateral OA, symptoms must be more intense in the right knee.
• Radiographic evidence of Grade 2 or 3 knee OA using the Kellgren-Lawrence Scale.
• Patients must have moderate or greater clinically significant pain on most days during the past month (more than 15 days out of 30, of average daily pain of >3/10).
• Average pain intensity and level of function within the range of 3-7 on the WOMAC scale, a subset score of the KOOS.
• At least a 10th grade English-reading level; English can be a second language provided that the patients feel they understand all the questions used in the assessment measures.

Exclusion Criteria:

• Any interventional procedure for knee pain, including corticosteroid injections (within 2 months) to the knee.
• Prior acupuncture treatment for any condition. Because we are using a placebo needle as a control, acupuncture-naive patients are necessary to maximize the benefits of blinding and to control expectancy.
• The intent to undergo surgery during the time of involvement in the study.
• Presence of any illness or medication use that is judged to interfere with the trial. For example: skin irritations around the knee such as psoriasis; bleeding disorders or anticoagulant use that would be contraindications for acupuncture
• Knee pain due to other causes, such as inflammation or malignancy, other pain disorders that may refer pain to the leg, OA of ipsilateral hip, diagnosis of RA.
• Non-ambulatory status.
• History of cardiac, respiratory, or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcome. For example: asthma or claustrophobia.
• Presence of any contraindications to fMRI scanning. For example: cardiac pacemaker, metal implants, fear of closed spaces, pregnancy.
• Instability of pain rating within Session 1 or Session 2 of Experiment One or Visit 1 of Experiment Two.