Background <p>Insufficient evidence exists regarding the characteristics of elderly patients with presarcopenia and their prognosis. Therefore, we aim to investigate the impact of preoperative presarcopenia on postoperative outcomes in elderly patients with resectable colorectal cancer.</p> Methods <p>We included patients aged ≥ 75&#xa0;years who underwent curative resection between June 2009 and December 2019. The psoas muscle index was calculated based on the computed tomography scan at the L3 level (lumbar area). The primary outcome was the difference in overall survival based on the presence or absence of presarcopenia. The secondary outcomes included differences in the occurrence of postoperative complications, tumor recurrence, and the impact of adjuvant chemotherapy on survival rates in high-risk stage II cancer.</p> Results <p>We included 325 patients (presarcopenia: 63) in this study. The presarcopenia group was older than the normal group (<i>p</i> = 0.02), with a lower body mass index (<i>p</i> &lt; 0.001). Preoperative blood test results indicated a higher frequency of anemia (<i>p</i> = 0.002), hypoalbuminemia (<i>p</i> = 0.009), and a higher neutrophil-to-lymphocyte ratio (<i>p</i> = 0.012) in the presarcopenia group. Postoperative complications did not differ significantly between the two groups (<i>p</i> = 0.989). In multivariate analysis, presarcopenia emerged as a significant factor affecting overall survival (HR 1.75, 95% CI 1.15–2.67, <i>p</i> = 0.009), but not recurrence-free survival (HR 1.48, 95% CI 0.86–2.55, <i>p</i> = 0.156). Presarcopenia in high-risk stage II colorectal cancer appeared to be a factor where adjuvant chemotherapy did not influence overall survival (HR 1.70, 95% CI 0.40 – 7.26, <i>p</i> = 0.475).</p> Conclusion <p>In patients with poor overall survival associated with presarcopenia, adjuvant chemotherapy should be selectively considered.</p>