To investigate seminal antioxidant systems and their correlation with hormonal pattern in varicocele patients, we studied 33 varicocele (VAR) patients (12 oligozoospermic, 21 normozoospermic) and 34 non-VARs (10 idiopathic oligozoospermic, 24 normozoospermic). Non-enzymatic total antioxidant capacity (TAC) was measured using H(2)O(2)-metamyoglobin, which generates the radical form, spectroscopically detectable, of the chromogen 2,2',-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS): time till appearance (Lag) of ABTS*(-) signifies antioxidant concentration. Lag was significantly longer in VARs than controls suggesting ineffective utilization of antioxidants. A significant direct correlation (r = 0.65, p < 0.01) of Lag with sperm count was observed in non-VARs, while in VARs it was inverted, as well as with hematic FSH levels. A multivariate analysis including FSH, Lag, progressive spermatozoa, oligozoospermia and varicocele indicated a strong inverse correlation between FSH and motility (r(2) = 0.31, p > F = 0.0007), not modified by Lag (r(2) = 0.31, p > F = 0.002). Their inverse correlation with Lag may suggest that higher FSH levels, improving sperm antioxidant efficiency, counterbalance varicocele-induced dyspermia.