Class of 2017 Abstract / Objectives: To determine the efficacy and toxicity of fluorouracil/leucovorin/oxaliplatin (FOLFOX) versus capecitabine/oxaliplatin (XELOX) in the treatment of colorectal cancer (CRC) in the adjuvant (aCRC) and metastatic (mCRC) setting in Veterans at the Southern Arizona Veteran Affairs Health Care System (SAVAHCS). Methods: A retrospective chart review was conducted to collect efficacy and toxicity data. Subjects were included based on age, treatment setting and regimen in the preset 5-year period, and appropriate diagnosis via International Classification of Diseases-Revision 9 (ICD-9) codes. Efficacy was measured via 1-year disease-free survival (DFS) for aCRC, progression-free survival (PFS) for mCRC, and overall survival (OS) for both settings. Results: A total of 79 subjects were initially enrolled with 51 and 54 all-male subjects included in the efficacy and toxicity analysis, respectively. Mean range of age was 63-72 years old. Subjects were divided into four groups: FOLFOX aCRC (17) and mCRC (19), XELOX aCRC (10) and mCRC (8). No difference was found in 1-year DFS and OS between aCRC groups, and PFS between mCRC groups; a higher incidence of 1-year OS with FOLFOX in the mCRC setting was noted (p = 0.03). No difference was found in toxicity between FOLFOX and XELOX, except a higher incidence of hand-foot syndrome in XELOX (p = 0.0007). Conclusions: Efficacy between FOLFOX and XELOX in aCRC and mCRC is similar, while toxicity is slightly more prevalent in XELOX due to increased hand-foot syndrome incidence. These findings agreed with the results reported by prospective clinical trials.