Locoregional delivery of anticancer drugs is an attractive approach to minimize adverse effects associated with intravenous chemotherapy. Polymer-based drug depots injected or implanted intratumorally or adjacent to the tumor can provide long-term local drug exposure. This review highlights studies in which drug-eluting depots have been applied locally in the treatment of cancer. In many cases such drug depots are used for prevention of tumor recurrence after surgery to eradicate remaining tumor cells. Clinical success has been reported for the treatment of brain cancer and liver cancer, and preclinical studies showed proof-of-concept for inhaled drug depots in lung cancer and intraperitoneally injected depots for the treatment of abdominal cancer.