Introduction: There is a decline in male fertility thus new treatments are needed. Aims: To test the efficacy of a new dietary supplement developed in the USA and registered as a curing drug in Hungary (OGYI). Methods: In a clinical trial 100 men with low sperm quality (spermium count 5–20 M/ml, good motility 10–40%, and adverse shape 30–50%) were examined. Results: Sperm parameters were measured before and after a 3-month treatment and after another 3-month without treatment. This dietary supplement statistically and clinically significantly improved sperm count and motility. In 74 cases this dietary supplement demonstrated a beneficial effect on sperm quality (more than 10% increase in sperm count, or quality of motility, or shape); in 16 cases the improvement exceeded 30%. No adverse effect could be accounted for this treatment. Conclusions: This new dietary supplement may contribute to the treatment of male infertility. Orv. Hetil., 2012, 153, 1787–1792.