Purpose: Micronised purified flavonoid fraction (MPFF) is a phlebotropic drug improving venous tone, elasticity and lymphatic drainage, decreasing venous distensibility, venous emptying times, reflux time of venous blood and capillary hyperpermeability, and having antioxidant activities. Since varicocele is a venous pathology, we evaluated the effects of MPFF on pain, spermiogram and color Doppler parameters in patients with painful varicocele. Material and Methods: Semen analyses and Doppler sonography were performed in 16 patients ( aged 20 - 62 years, mean 31.2 +/- 10.9) before and after 1,000 mg/day MPFF treatment. Pain change was assessed with visual analogue scale scored between 0 and 10. Patient satisfaction with outcome and side effects were recorded. Results: Mean pain scores at 1, 3, and 6 months were 1.25 +/- 1.34, 0.25 +/- 0.68, and 0.12 +/- 0.34, respectively, all being significantly lower ( p < 0.001 for each) than baseline ( 4.93 +/- 1.77). Mean score at 12 months (0.93 +/- 1.06) was still lower than baseline ( p < 0.001) but higher than at 6 months ( p = 0.019). Respectively, 14 (87.5%) and 2 (12.5%) patients reported complete and very significant resolution of pain at the 6th month. All patients were very satisfied with the outcome. While semen volume, total sperm count, sperm concentration and morphology did not change significantly, motility increased significantly ( p = 0.009) due to decrease of grade 0 sperms ( p = 0.006) and increase of grade 3 + 4 sperms ( p < 0.001). Reflux time of left spermatic vein during the Valsalva maneuver decreased significantly ( p = 0.003). No significant change occurred in reflux time of the right spermatic vein. No side effect was recorded. Conclusions: Results of this preliminary study suggest the safety and efficacy of MPFF in the treatment of varicocele-associated pain. However, no recommendation for the use of MPFF in the treatment of pain associated with varicocele can be made before these preliminary results are confirmed by a randomized placebo-controlled trial. Copyright (C) 2005 S. Karger AG, Basel.