Background: The increase in survival seen in recent years in patients with mCRC has been attributed to improvements in treatments, including the introduction of targeted biologic agents. The objectives of this retrospective, observational study are to investigate recent treatment patterns in US mCRC patients and examine real-world survival outcomes. Methods: Data were obtained from a large U.S. database (SDI/IMS Health) of mCRC patients diagnosed from January 1, 2004 to June 30, 2011, =18 y at diagnosis, and who received chemotherapy and/or biologic treatment. Complete follow-up was defined as those who either died before June 2011 or who had at least 1 claim within 30 days of June 30, 2011. Kaplan-Meier curves were generated to determine overall survival (OS) from the date of mCRC diagnosis. Results: 1,066 stage IV mCRC patients with complete follow-up were identified (57.5% male; mean age, 61.6 y). Approximately 80% were diagnosed with mCRC after 2006; 51.7% had liver metastases. The most common 1L, 2L, and 3L regimens were FOLFOX plus bevacizumab (34.52%), FOLFIRI plus bevacizumab (21.83%), and irinotecan plus cetuximab (15.83%), respectively. A total of 445 patients died during the study period, yielding a mortality rate of 41.74%. Mean time from diagnosis to first treatment was 3.31 months (SD=7.13). All patients received 1L therapy; OS from diagnosis was 35.77 months (95% CI: 32.57-38.10); 5-year survival was approximately 28%. After 1L, 591/1066 (55%) patients went on to receive 2L therapy; for these patients, median survival from diagnosis was 37.13 months (95% CI: 34.07-40.43) and 5-year survival was approximately 25%. After 2L, 278/591 (47%) patients received 3L therapy; for these patients, median survival from diagnosis was 38.10 months (95% CI: 34.83-43.13); 5-year survival was approximately 25%. Conclusions: In this study, OS (35.77 months) was longer than for other mCRC observational studies that have reported survival from start of treatment, but is more comparable when the ~3 months from diagnosis to start of treatment are not included. Addition of targeted agents and novel chemotherapy has prolonged OS in mCRC patients. Because of poor 5-year survival rates, the need for additional agents in later lines of therapy still exists.