Background: Breast cancer is the second most common cancer in humans. Its therapy procedures such as breast biopsy can cause anxiety and persistent pain in patients. Virtual reality (VR) has been applied to promote comfort in various populations. However, the effectiveness of VR in relieving pain and anxiety in patients undergoing breast cancer treatment is unclear. Purpose: This study was designed to examine the effect of VR on anxiety and pain in people undergoing treatment for breast cancer. Methods: PubMed, Cochrane, Embase, Scopus, Web of Science, and MEDLINE databases were searched for studies involving VR, pain, and anxiety in patients with breast cancer published up to March 2022. The Cochrane Handbook for Systems quality evaluation standard 6.3.0 was followed to assess risk of bias in the identified studies, with the results reported in line with the Preferred Reporting Items for Systematic Reviews and Meta- Analyses statement. Subsequently, a meta-analysis of the included data was conducted using RevMan 5.3 software. Results: Six randomized controlled trials and one quasi-experimental study were included. The strength of the evidence ranged from moderate to high. Although VR was found to ameliorate anxiety in patients with breast cancer, only three studies showed statistically significant changes. All of the included studies reported statistically significant improvement in pain levels. In addition, two of the studies reported cybersickness symptoms as a common side effect of VR. Conclusions: VR has an important role to play in alleviating pain in patients with breast cancer. However, evidence demonstrating VR's importance in alleviating anxiety symptoms in this population is insufficient. Studies conducted with larger sample sizes and high-quality research methodologies will be necessary to clarify this issue. Clinical nurses should address the potential side effects of VR.