The study objective is to microscopically evaluate the morphology of sperm in patients with varicocele after surgical treatment and therapy with Prostatilen® AC. Materials and methods. The treatment group included 20 males between 26 and 45 years of age (mean age 31.6 ± 6.1 years) with various stages of varicocele and fertility problems; among them, 10 patients with subclinical stages of varicocele received conservative treatment with Prostatilen® AC (group 1) and were examined before and after the treatment; 10 males with infertility caused in part by varicocele of the spermatic cord veins were examined 6 months to 3 years after surgical treatment (group 2). Standard clinical and lab tests, sperm analysis, electron microscopy of the ejaculate were performed. The control group included 65 fertile males whose sperm samples were obtained from a bank of reproductive cells and tissues and used for comparison in microscopic examination. Results. In patients who received conservative treatment the number of sperm with immature chromatin decreased (p = 0.045) compared to the control group. This characteristic differed in patients after varicocelectomy and patients after conservative treatment (p = 0.037). Compared to control, the number of sperm with excess residual cytoplasm in the head and neck was higher in patients after varicocelectomy (p = 0.011). After conservative treatment, the number of sperm with excess residual cytoplasm was close to the control number and lower than in patients after varicocelectomy (р = 0.028). Conclusion. In patients with subclinical varicocele, conservative treatment with Prostatilen® AC leads to significant improvement in sperm ultrastructure compared to patients who underwent surgery to treat this pathology. © 2019 Andrologia i Genital'naa Hirurgia. All rights reserved.