Background: Medically unexplained physical symptoms (MUPS) are common and difficult to treat. Aim: To investigate the effectiveness of adding five-element acupuncture to usual care in ‘frequent attenders’ with MUPS. Design and setting: Randomised controlled trial in four London general practices. Method: Participants were 80 adults with MUPS, consulting GPs ≥8 times/year. The intervention was individualised five-element acupuncture, ≥12 sessions, immediately (acupuncture group) and after 26 weeks (control group). The primary outcome was 26-week Measure Yourself Medical Outcome Profile (MYMOP); secondary outcomes were wellbeing (W-BQ12), EQ-5D, and GP consultation rate. Intention-to-treat analysis was used, adjusting for baseline outcomes. Results: Participants (80% female, mean age 50 years, mixed ethnicity) had high health-resource use. Problems were 59% musculoskeletal; 65% >1 year duration. The 26-week questionnaire response rate was 89%. Compared to baseline, the mean 26-week MYMOP improved by 1.0 (95% confidence interval [CI] = 0.4 to 1.5) in the acupuncture group and 0.6 (95% CI = 0.3 to 0.9) in the control group (adjusted mean difference: acupuncture versus control –0.6 [95% CI = –1.1 to 0] P = 0.05). Other between-group adjusted mean differences were: W-BQ12 4.4 (95% CI = 1.6 to 7.2) P = 0.002; EQ-5D index 0.03 (95% CI = –0.11 to 0.16) P = 0.70; consultation rate ratio 0.90 (95% CI = 0.70 to 1.15) P = 0.4; and number of medications 0.56 (95% CI = 0.47 to 1.6) P = 0.28. All differences favoured the acupuncture group. Imputation for missing values reduced the MYMOP adjusted mean difference to –0.4 (95% CI = –0.9 to 0.1) P = 0.12. Improvements in MYMOP and W-BQ12 were maintained at 52 weeks. Conclusion: The addition of 12 sessions of five-element acupuncture to usual care resulted in improved health status and wellbeing that was sustained for 12 months.