Background: CRC is the second leading cause of cancer-related death, and 40-50% of patients are older than 70 years. Frailty is a concept that has been proposed by geriatricians as an indicator of functional age. The EFS is a 15 point incremental scale; it is quick (<5 min), and simple to administer. We conducted a pilot study to establish if the EFS would add utility beyond clinician’s expertise. The primary objective was to determine if there was an association between the EFS and receipt of chemotherapy. Methods: The EFS was administered to stage II-IV CRC patients ≥70 years, referred to a Medical Oncologist at a tertiary care centre. The EFS was completed by one of the investigators, with the treating oncology team blinded to results and a follow up 14 month chart review. Results: Forty-six patients were enrolled with the following characteristics: average age 76, 48% male, 78% performance status (PS) 0-1, and 21 (46%) started chemotherapy. The EFS was reproducible between visits (r = 0.81 [CI 0.64-0.9, p<0.0001]). There was no correlation between the EFS and receipt of chemotherapy for the study population as a whole. As none of the 16 stage II patients had high-risk features requiring chemotherapy, the analysis was repeated excluding these patients. There was a reduced likelihood of receiving chemotherapy for stage III/IV patients with higher EFS scores (Odds ratio 0.56 [CI 0.37-0.85, p<0.01] per unit increment). A similar effect was observed after multivariable analysis (adjusting for PS, age, stage and gender, Odds ratio 0.41 [CI 0.18-0.96, p<0.05] per unit increment). No correlation existed between EFS and upfront dose reductions, choice of less toxic regimens, or hospitalization secondary to grade 3/4 toxicities. Conclusions: This pilot study suggests the EFS can identify patients that Oncologists may have thought were too frail for chemotherapy, independent of PS. Therefore, the EFS has the potential to add a reproducible, and quantifiable measure of frailty to the clinician’s decision making armamentarium. The next study phase will employ the EFS real-time, and determine if using the EFS can minimize complications and unplanned health care utilization in elderly cancer patients.