Aim: The aim of this study was to evaluate the efficacy and side effects of silymarin in the treatment of CIPN. Methods: Patients who referred to outpatient oncology department of a referral educational hospital affiliated to Mazandaran University of Medical Sciences and experienced CIPN were randomized to receive silymarin or placebo. Intervention group received 140 mg of the Silymarin twice daily accompanied and 300 mg/day Gabapentin, whereas control group received 300 mg/day of Gabapentin and placebo twice daily for 3 months. The grade of neuropathy was determined according to the CTCAE criterion. The improvement of neuropathy was defined as the reduction of at least one neuropathic score. The visual analogue scale (VAS) was used to assess the severity of patients’ pain and the EORTC-QLQ-C30 criterion was used to assess the quality of life. Patients were evaluated initially and at the follow up visit 3 months after the enrollment. Results: A total of 80 patients were enrolled in the study. There was no significant difference between the groups in terms of severity of neuropathy at baseline. At the end of the study, the number of people with improved neuropathy in the silymarin group was 82.8% patients, which was significantly higher than 48.4% observed in the patients received placebo (P= 0.005). The silymarin-treated group showed a significant reduction in pain compared with those receiving placebo. Despite the improvement in quality of life in the intervention group compared to the comparison group, this difference was not statistically significant. Gastrointestinal symptoms were the only reported side effects with a similar incidence in two groups. Conclusion: The present data demonstrate the potential clinical use of silymarin as an adjuvant therapy to reduce CIPN symptoms.