Objective: Sarcopenia is the age-related loss of muscle mass, strength, and function. It is a common finding in older patients and is associated with decreased life expectancy and potentially higher susceptibility to chemotherapy toxicity. This study describes the prevalence of sarcopenia in older adults with early stage colorectal cancer. Materials and Methods: Patients ≥. 70 years old who underwent surgical resection for stage I-III colorectal cancer between 2008 and 2013 were identified from the medical record. Sarcopenia was assessed by measuring the total muscle area on computerized tomography (CT) images obtained prior to surgery. Total muscle area was measured at the level of L3 and normalized using each patient's height to produce a skeletal muscle index (SMI). Sarcopenia was defined using sex- and body mass index (BMI)-specific threshold values of SMI. Results: Eighty-seven patients were included, with a median age of 77 years (70-96). Twenty-five men (60% of 42) and 25 women (56% of 45) had sarcopenia. Sarcopenic patients had significantly lower BMI (p = 0.03) compared to non-sarcopenic patients. There was a positive correlation between BMI and SMI for both men (r = 0.44) and women (r = 0.16). Conclusion: Sarcopenia is highly prevalent among older patients with early stage colorectal cancer. BMI alone is a poor indicator of lean body mass and improved methods of screening for sarcopenia are necessary. CT scans are a viable option for identifying sarcopenic patients in whom timely interventions may improve survival, quality of life, and functional outcomes.