Samples of seminal fluid were obtained from two groups of patients undergoing to a IVF cycle: healthy subjects and subjects with oligoasthenospermia (OA, < 15 mil/ml). The collected samples were submitted to optic microscopy in order to evaluate semen's volume, spermatozoa's number and motility, during the initial semen analysis and after density gradient separation method; these parameters were evaluated before and after the administration of 4000mg/die of myo-inositol associated to 400 µg of folic acid for three months.