Local anesthetics are voltage-gated sodium channel blockers primarily administered locally or to the innervating nerves for anesthetic or analgesic purposes. In vitro studies have found direct effects of local anesthetics on cancer cells, such as impact on cancer cell proliferation, apoptosis, migration, invasion, and chemosensitivity, by multiple mechanisms. So far, in vivo evidence regarding the effect of local anesthetics on cancer cell lines is relatively lacking. Local and regional anesthesia administration has been reported to reduce postoperative pain and opioid use in cancer treatment. Additionally, regional anesthesia may reduce the perioperative stress response. However, the clinical therapeutic application of local anesthetics in cancer remains exploratory. In this review, we will discuss the direct and indirect effects of local anesthetics on cancer cells, and discuss the current evidence related to the use of local anesthetics in the treatment of cancer.