To evaluate the efficacy of keishibukuryogan, a traditional Kampo formula known to be an anti-Oketsu (impaired microcirculation and non-physiological blood congestion) drug, in combination with an anti-oxidant for the treatment of varicoceles.We retrospectively analyzed 119 patients with palpable and subclinical varicoceles who were treated with 7.5 g/day of keishibukuryogan and 600 mg/day of tocopherol nicotinate. Their motile sperm concentrations at the start of medication and after 3 months were compared. As a subgroup analysis, a comparison test was carried out between patients with a high-grade varicocele and those with a low-grade varicocele.The mean age of the study patients was 35.6 years. Among them, 17, 41, 44 and 17 had subclinical, grade 1, grade 2 and grade 3 varicoceles, respectively. Overall, the differences in motile sperm concentration (millions/mL) before and after treatment were not significant (median 0.58, 95% confidence interval -0.12 to 1.56; P = 0.115). The results of the subgroup analysis showed that the motile sperm concentration in patients with a low-grade varicocele significantly increased (median 1.21, 95% confidence interval 0.45-2.47; P = 0.024); however, no significant improvements were seen in patients with a high-grade varicocele.The results of the present study showed that the combination of keishibukuryogan and an anti-oxidant had a limited effect on varicoceles, but they suggest that it is effective for the treatment of low-grade varicoceles.