Background: Elderly patients with mCRC are underrepresented in clinical trials. For this reason, the optimal treatment in this population is uncertain. The aim of this study is to compare efficacy and safety outcomes in patients with mCRC treated in our institution according to age (<65 vs ≥65 years). Methods: We conducted a retrospective analysis of 482 patients with mCRC attended in the Hospital Gregorio Marañón (Spain) between January 2010 and 2018. Results: Patients characteristics table. First-line: chemotherapy (CT) 98.7% vs 97.3% respectively (p=0.324), biologic agents (BA) 81.2% vs 79.0% (p=0.585). Significantly more <65-year-old patients received FOLFOX (60.5% vs 44.4%) and more ≥65-year-old patients XELOX (9.2% vs 17.5%) or capecitabine (2.0% vs 7.5%). Second-line: CT 64.9% vs 63.5% (p=0.764), BA 60.4% vs 51.1% (p=0.055). Significantly more <65-year-old patients received FOLFIRI (67.0% vs 54.5%) and more ≥65-year-old patients irinotecan (2.0% vs 8.6%). Third and subsequent lines: Significantly more young patients received a third-line (CT: 41.6% vs 31.0%; BA: 24% vs 21.6%), fourth-line (CT: 22.1% vs 11.9%; BA:16.2% vs 6.4%) and fifth-line of treatment (CT: 11.7% vs 5.8%; BA: 4.5% vs 3.6%). More young patients underwent metastasis resection (74.0% vs 58.1%, p=0.001). There were no differences in rate of post-operative complications (p=0.840). There were no differences in overall survival (36.05m vs 28.06, p=0.142), progression-free-survival (first-line: 12.73m vs 11.78m, p=0.139; second-line: 8.78m vs 62.71m, p=0.254) or adverse event rate (73.4% vs 73.6%, p=0.967). Conclusions: Intensive treatment could be an effectiveness and safe option in selected elderly patients.