When, in 1975, I successfully performed my first left spermatic vein sclerotherapy [1], I was a young doctor and I didn’t know that scrotal varicocele could produce infertility. Moreover, I had never imagined that this simple and personal technique could, in such a short time, become a very interesting but controversial subject for so many medical specialists, such as andrologists, urologists, androurologists, gynaecologists, surgeons, endocrinologists, and interventional radiologists, therefore causing many endless discussions. I am replying to you because I believe that young interventional radiologists must not be so excited by an excessive therapeutic enthusiasm; I think they should be free to establish the most appropriate therapy and rational indications. Scrotal varicocele represents an important social and sanitary problem, affecting approximately 15%–20% of young males; reversible infertility (subfertility) and, sometimes, irreversible testicular damage are observed in 20%–40% of them. The remaining 60%–80% with clinically manifested varicocele do not have fertility problems. Since we are dealing with high numbers (about 150,000 males per million) and since the varicocele is bilateral in 70% of cases, then we should treat approximately 60,000 (40% of 150,000) varicoceles on the left and 42,000 (70% of 60,000) on the right side, amounting to 102,000 per million males. Such a huge number is obviously not conceivable even in rich countries! Nevertheless, we should always keep in mind that infertility is primarily attributed to female causes (58% of cases), whereas male causes amount only to 25% of cases, while in 17% of couples it is unexplained. My clinical maneuver, performed always with ultrasound (US) color Doppler examination, deliberately ignores the question of the so-called ‘‘subclinic varicocele’’! We recommend the use, for US assessment, of the five degrees of Sarteschi’s classification [2], in which the first degree concerns subclinical varicocele, characterized only by upper inguinal reflux without scrotal pampiniform plexus dilations. Moreover, in my opinion and in many others’, subclinic varicocele is not considered one of the causes of male infertility. In fact, when I was invited to the III World Congress of Andrology in Tel Aviv (Israel), to give a lecture at the ‘‘Varicocele Symposium’’ [3], I found an unanimous consensus among the most important andrologists of the world to avoid treating not only subclinic but also small varicoceles. This consensus has been recently confirmed by Nagler [4]. On the other hand, it is obvious that a high US grade (5th) left scrotal varicocele is very often the cause of the so-called ‘‘false bilateral varicocele,’’ characterized by dilation of the right pampiniform plexus due to anasthomotic trans-septal vessels [5]. In these cases the right dilation spontaneously disappears after treatment of the left side. In fact, in the case of the left and low-degree varicocele, we never see a bilateral dilation, except in the true bilaterality. This condition can explain why 60%–80% of clinically manifested left varicoceles are curiously fertile, probably because of the lack of scrotal trans-septal collateral veins to the other side, because only the left testis is functionally V. Iaccarino Department of Radiological Sciences, Faculty of Medicine, University of Naples ‘‘Federico II,’’ Naples, Italy