Pancreatic, gastric, and colorectal cancers are major causes of morbidity and mortality worldwide. When curative surgical resection is not an option, these malignancies tend to respond very poorly to chemotherapy and carry a dismal prognosis. There is, therefore, an urgent need for novel treatment strategies for these cancers. Great strides have been made in colon cancer treatment with the recent introduction of several novel agents, including capecitabine, irinotecan, and oxaliplatin either alone or in combination regimens. Treatment of advanced colon cancer, however, remains essentially palliative, and treatment-related toxicity remains a significant problem. The treatment of advanced gastric and pancreatic cancer has also seen the introduction of new agents, such as gemcitabine and irinotecan; however, the impact of these agents on survival has been small, and toxicity continues to be a major obstacle. The search for new chemotherapeutic agents and treatment strategies will need to focus on improving outcomes and safety and tolerability profiles. To date, several new agents have shown promise, including pemetrexed, G17DT, bevacizumab, and other targeted agents. Further research into their optimal use either alone or in combination regimens should be a priority.