OBJECTIVE To investigate the clinical effects and safety of electroacupuncture (EA) in the treatment of overactive bladder (OAB) refractory to first-line anticholinergic treatment. METHODS Women diagnosed with OAB who were refractory to first-line anticholinergic treatment were referred for EA therapy. 50 women enrolled in this single-blind randomised controlled trial and were randomised 1:1 to EA or sham EA (SEA). The EA and SEA groups were treated with 30 sessions (5 sessions a week for 6 weeks), and each session lasted 30 min. OAB symptom scores (OABSS), King's Health Questionnaire scores (KHQ) and urodynamic parameters were used to assess treatment effects. Safety was also evaluated. RESULTS 45 women completed all aspects of the study (23 in the EA group and 22 in the SEA group). The OABSS and KHQ showed statistically significant improvements in the EA group compared with the SEA group after 6 weeks of treatment (p<0.05). There were no statistical differences in the maximum ﬂow rate and postvoid residual (p>0.05), but there were statistical improvements in the first sensation of bladder filling, first urge to void and maximum cystometric capacity (p<0.05) in the EA group compared with the SEA group. No serious adverse events occurred in either group. CONCLUSIONS EA appears to be an effective, safe and minimally invasive treatment for women with OAB. Further studies with longer follow-up are needed to evaluate whether it could be a therapeutic option for OAB refractory to treatment with anticholinergics.