Objectives : To compare the efficacy of local acupoint with distal acupuncture at relieving pain and improving function in knee osteoarthritis. Designs : A randomized, single-blinded, crossover clinical trial. Settings : One outpatient clinic(department of acupuncture & moxibustion) located in academic teaching hospital, South Korea. Patients : 17 patients with osteoarthritis of the knee(mean age 62.76[$SD{pm}4.37$] years). Interventions : The trial had 4 stages : baseline(2weeks), phase I and II(each 2weeks), washout period(2weeks). Patients were randomly assigned to either group A or group B. Group A received acupuncture at local acupoints during phase I, then acupuncture at distal acupoints in phase II. Group B received the treatments in reverse order. In each phase, the patients were treated with acupuncture for 6 times. Measurements : The primary outcome was subjective pain as measured by a 100mm visual analogue scale(VAS) ranging from 0(no pain) to 10(worst pain ever). Secondary outcomes were changes in the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC) total and pain scores. Measurements were obtained at baseline, 1st day of phase I and II, and 2 days after last treatment of phase I and II. Results : The 17 participants in 2 groups were well matched for age, sex, target knees, baseline VAS score, WOMAC pain score and WOMAC score. Participants in local acupoint group experienced greater improvement than distal acupoint group at 2 days after last treatment in WOMAC total score(mean difference, -10.65[95% CI, -20.56 to -0.74] ; P=0.036) but not in VAS(mean difference, -12.41[95% CI, -29.56 to 4.73] P=0.15) and WOMAC pain score(mean difference, -1.82[95% CI, -3.98 to 0.33] ; P=0.094). Conclusions : Local acupoints are more effective than distal acupoints at relieving pain and improving function in knee osteoarthritis.