Background: Patients with colorectal cancer (CRC) commonly present with gastrointestinal (GI) bleeding and are at risk of developing protein-energy malnutrition (PEM) either due to effects of therapeutic interventions (chemotherapy, immunotherapy, radiation) or primary disease on appetite and caloric intake. There are several existing studies on CRC and gastrointestinal hemorrhage, however the impact of concurrent PEM on in-hospital outcomes for patients with CRC admitted for GI bleeding is unclear. Our study aims to assess the association of PEM and clinical outcomes among patients with CRC hospitalized for GI bleeding. Methods: We analyzed data from the 2020 National Inpatient Survey on patients with CRC who were admitted with GI bleeding. To determine our study sample, we used International Classification of Diseases, 10th Revision (ICD10) codes for CRC (C18.X, C19 and C20), and GI bleeding (K92.2 and K62.5). The primary exposure was a comorbid diagnosis of PEM (defined based on the ICD 10 codes E40 – E46). The clinical outcomes assessed in this study were all-cause mortality, sepsis, septic shock and length of stay in the hospital. A multivariate logistic regression was used to assess the association of comorbid PEM with all-cause mortality and sepsis. A cox proportional hazard regression was used to investigate the association between the PEM and time to discharge. Covariates adjusted for in our final analyses included age, sex, insurance status and number of comorbidities present on the patients record at discharge. Results: Of the 2223 patients with CRC who were admitted for GI bleeding, 55% were male, 64% were White and mean age was 63 years (SD 14.2). A quarter (23%) had comorbid PEM, 14.6% had sepsis and 5.4% had septic shock. About 6.5% died during hospitalization and the mean length of hospital stay was 7.8 days. Comorbid PEM was significantly associated with a two-fold increase in the risk of all-cause in-hospital mortality (aOR 2.05; 95% CI: 1.41 – 3.98), sepsis (aOR 2.33; 95% CI: 1.78 – 3.05) and septic shock (aOR 2.0; 95% CI:1.35 – 3.09). Additionally, compared to patients without PEM, those with concomitant PEM had a lower discharge rate (HR 0.71, 95%CI: 0.64-0.78). Conclusions: Our study demonstrated that comorbid PEM in patients with CRC hospitalized for GI bleeding is associated with increased risk of all-cause in-hospital mortality, sepsis, septic shock and prolonged length of stay. The findings from this study highlight the need for nutritional considerations when managing patients with CRC and GI bleeding to prevent adverse health outcomes and potentially improve survival among these patients.