An increasing number of patients with complicated systemic comorbidity can undergo colorectal cancer (CRC) surgery. Such patients have a high risk of developing poor postoperative outcomes. This study aimed to identify preoperative factors, including nutritional and sarcopenia statuses, leading to poor postoperative outcomes in patients with severe systemic comorbidities. This study included 114 patients who underwent radical CRC resections and had American Society of Anesthesiologists Physical Statuses ≥3. We retrospectively analyzed the relationships between clinical factors, postoperative complications (within 28 days postoperatively and Clavien-Dindo classification grade ≥2), length of hospital stay, discharge destination, and overall survival (OS). The median patient age was 74.5 years (range=41.0-93.0 years). Thirty-six patients had postoperative complications (31.6%), and the risk factors in the multivariate analyses were rectal cancer and preoperative nutritional disorders with Prognostic Nutritional Index ≤40. In patients with nutritional disorders, the postoperative hospital stay was longer, and a higher (but not statistically significant) percentage were not discharged home. Moreover, the independent factors for OS identified in the multivariate analyses were body mass index (BMI) and hemodialysis. In patients with CRC and severe systemic comorbidities, those with Prognostic Nutritional Index ≤40 have a high risk of developing postoperative complications, leading to a prolonged postoperative hospital stay and possibly preventing discharge home. Additionally, among these patients, OS was poor in those with low BMI or preoperative hemodialysis.