INTRODUCTION AND OBJECTIVE: Although the standard 12-weeks percutaneous tibial nerve stimulation (PTNS) for refractory overactive bladder (OAB) is effective, standard PTNS is costly. We aim to compare the efficacy of shortened PTNS versus sham for refractory OAB. METHODS: 57 non-neurogenic OAB adult patients were randomized to 6 weeks PTNS group or sham group. The PTNS group (25 patients) was treated with active PTNS, the sham group (25 patients) received a placebo treatment using a 34 gauge needle placed in the medial part of the gastrocnemius muscle. both groups had one session, lasted 30 minutes, performed 3 times weekly for 2 weeks. The primary outcome to assess symptoms improvements assessed by Homma and Blaivas OAB symptoms scores as well as 3-day voiding diaries at baseline, 7th week, 3rd, and 6th month. RESULTS: Patients baseline characteristics were comparable between groups (table 1). The 7th week, 3rd and 6th month OABSS demonstrated that PTNS achieved statistically significant improvement with 52% of patients reported voiding dairy (p <0.001) . Compared to sham group, the voiding dairy improved in patients with previous Botox with PTNS with p <0.001 (table 2). CONCLUSIONS: A shortened 6-week treatment protocol with PTNS appears to be successful and more effective than sham in the treatment of refractory OAB. 6-week treatment PTNS would make it more acceptable and cost effective for patients.Source of Funding: No