To evaluate the efficacy of adjuvant, capacitive resistive monopolar radiofrequency (CRMRF, INDIBA) treatment at 448 kHz together with physiotherapeutic techniques compared to a sham treatment with the same techniques, for pain reduction and quality of life (QoL) improvements in patients with chronic pelvic pain syndrome (CPPS). A triple-blind, randomized controlled trial (RCT) including patients with CPPS randomly allocated (1:1) to a CRMRF-activated group (intervention) or a CRMRF-deactivated one (control). Both groups received physiotherapeutic techniques and pain education weekly for 10 consecutive weeks. Data from a visual analogical scaleand the SF-12 questionnaire were collected at trial commencement and repeated at the 5th and 10th sessions. Pain intensity was considered the main outcome. For the comparisons between variables, the χ2 and Student's ttest were used. Superiority was analyzed by estimating the mean change (95% confidence interval). Analysis was performed for the per-protocol and the intention-to-treat populations. The statistical significance level was set at p < 0.05. Eighty-one patients were included (67.9% women) with a mean age of 43.6 years (SD 12.9). CRMRF lessened pain scores by more than 2 points and improved QoL by 5 points. There were no relevant side effects and overall adherence to the treatment was 86.4%. This is the first RCT that evaluates the efficacy of CRMRF (INDIBA) compared to a sham treatment, and demonstrates its superiority in decreasing pain and improving QoL. Such results may lead to greater prescribing of CRMRF when treating CPPS patients.