© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.Objectives: The management of chronic pelvic pain syndrome (CPPS) is controversial because of the unclear pathogenesis of this disease. In one theory, prostatitis has been proposed to be associated with pelvic venous diseases such as varicocele and hemorrhoids, dilatation of the Santorini plexus. In this study, we investigated the effect of micronized flavonoid fraction (an agent used in venous insufficiency) in the treatment of type III CPPS. Methods: Patients diagnosed with type III chronic prostatitis were randomized and divided into 3 groups. Group 1 consisted of patients using antibiotics + anti-inflammatory + alpha-blocker (n = 47), Group 2 consisted of patients using antibiotics + anti-inflammatory + purified micronized flavonoid fraction (n = 45), and Group 3 consisted of patients using only purified micronized flavonoid fraction (n = 35). Results: The mean age of the patients was 32.93 ± 4.70 (range; 23–44) years. There was a statistically significant difference between the groups in terms of the 6th month NIH-CPSI (National Institute of Health Chronic Prostatitis Symptom Index) total scores (p =.000). Also, it was found that NIH-CPSI total scores at month 12 in Group 3 were significantly higher than those in Group 1 and 2 (p1 =.000, p2 =.002). NIH-CPSI total scores at month 12 in Group 2 were significantly higher than those in Group 1 (p =.000). Conclusion: The use of purified micronized flavonoid will decrease prostatic inflammation occurring due to increased perineal venous return.it can also be preferred as part of multimodal therapy because of its profile with relatively less side effects and being more affordable compared with alpha-blockers.