Decreasing the dose of human chorionic gonadotropin (hCG) used to trigger final oocyte maturation in assisted reproductive technology programs is regarded as a useful intervention in the prevention of ovarian hyperstimulation syndrome, but the minimal effective dose has not been yet identified. In this study, the capacity of a reduced dose of recombinant hCG (r-hCG) to provide adequate oocyte maturation was tested for the first time. Thirty-five high-responder patients received a dose of 125 µg (half of the standard dose) of r-hCG for triggering final oocyte maturation. The number of oocytes retrieved per patient and the proportion of mature oocytes were evaluated. As a result, a mean number of 14 oocytes were retrieved, of which 85% were found to be mature (MII). There was only one patient developing a moderate form of ovarian hyperstimulation syndrome and not requiring hospitalization. It is suggested that r-hCG at 125 µg can be effective in triggering final oocyte maturation in high-responder patients. Additional properly powered and controlled studies are needed to support this contention.