OBJECTIVE: To investigate the effectiveness and safety of acupuncture in persistent allergic rhinitis (PAR) DESIGN: Randomised, single-blind, sham-controlled trial conducted from May 2004 to February 2005. PARTICIPANTS AND INTERVENTION: 80 patients with PAR (age, 16-70 years) were randomly assigned to receive real or sham acupuncture. After a 1-week baseline period, participants were treated twice weekly for 8 weeks and followed up for another 12 weeks. MAIN OUTCOME MEASURES: Nasal obstruction, sneezing, rhinorrhoea and nasal itch were each self-assessed daily on a 5-point scale, and scores were aggregated weekly. The sum of the symptom scores (total nasal symptom score, TNSS) was also determined. A secondary outcome was use of PAR relief medication. RESULTS: After 8 weeks' treatment, the weekly mean difference in TNSS from baseline was greater with real (-17.2; 95% CI, -24.6 to -9.8) than with sham acupuncture (-4.2; 95% CI, -11.0 to 2.7) (P = 0.01). The decrease in individual symptom score was also greater with real acupuncture for rhinorrhoea (P < 0.01) but not the other symptoms. At the end of follow-up, the greater difference in TNSS from baseline in the real acupuncture group was still apparent: real, -21.0 (95% CI, -29.1 to -12.9) versus sham, - 2.3 (95% CI, -10.2 to 5.6) (P = 0.001). Moreover, the differences from baseline in all four individual symptom scores were greater for the real than for the sham group (P < 0.05). Real and sham acupuncture were both well tolerated. CONCLUSION: Our findings suggest that acupuncture is effective in the symptomatic treatment of PAR. TRIAL REGISTRATION: Australian Government Therapeutic Goods Administration CTN 034/2004.