Indole alkaloids, which are abundant in nature, are a significant source of pharmacologically active compounds. Indole alkaloids have the potential to exert anticancer activity via various antiproliferative mechanisms, and some of them, such as Vinblastine and Vincristinem, have already used in clinics or under clinical evaluations for the treatment of cancers. Therefore, indole alkaloids occupy an important position in the discovery of novel anticancer agents. This review emphasizes the recent development of indole alkaloids as potential anticancer agents, their structure-activity relationship, and mechanisms of action covering the articles published from 2015 to 2020.