BACKGROUND: The development and progression of cancer cachexia are connected to systemic inflammation and physical performance. However, few relevant studies have reported the survival outcomes prediction of systemic inflammation and physical performance in patients with colorectal cancer (CRC) cachexia. This study investigated the prognostic prediction value of systemic inflammation and performance status in patients with CRC cachexia. METHODS: This multicentre cohort study prospectively collected 905 patients with CRC (58.3% males, 59.3 ± 11.5 years old). Cancer cachexia was diagnosed according to the 2011 Fearon Cachexia Diagnostic Consensus. The prognostic value of systematic inflammatory indicators was determined using the area under the curve, concordance index, and multivariate survival analysis. Performance status was evaluated with Eastern Coopertive Oncology Group performance score (ECOG-PS). Survival data were analysed using univariate and multivariate Cox regression analyses. RESULTS: The area under the curve, concordance index and survival analysis showed that C-reactive protein (CRP), lymphocyte to CRP ratio (LCR) and CRP to albumin ratio (CAR) were more stable and consistent with the survival of patients with CRC, both in non-cachexia and cachexia populations. Among patients with CRC cachexia, high inflammation [low LCR, hazard ratio (HR) 95% confidence interval (95% CI) = 3.33 (2.08-5.32); high CAR, HR (95% CI) = 2.92 (1.88-4.55); high CRP, HR (95% CI) = 3.12 (2.08-4.67)] indicated a worse prognosis, compared with non-cachexia patients [low LCR, HR (95% CI) = 2.28 (1.65-3.16); high CAR, HR (95% CI) = 2.36 (1.71-3.25); high CRP, HR (95% CI) = 2.58 (1.85-3.60)]. Similarly, among patients with CRC cachexia, high PS [ECOG-PS 2, HR (95% CI) = 1.61 (1.04-2.50); ECOG-PS 3/4, HR (95% CI) = 2.91 (1.69-5.00]) indicated a worse prognosis, compared with patients with CRC without cachexia [ECOG-PS 2, HR (95% CI) = 1.28 (0.90-1.81); ECOG-PS 3/4, HR (95% CI) = 2.41 (1.32-4.39]). Patients with CRC cachexia with an ECOG-PS score of 2 or 3-4 and a high inflammation had a shorter median survival time, compared with patients with an ECOG-PS score of 0/1 and a low inflammation. CONCLUSIONS: The systemic inflammatory markers LCR, CAR and CRP have stable prognostic values in patients with CRC. The ECOG-PS may be an independent risk factor for CRC. Combined evaluation of systemic inflammation and ECOG-PS in patients with CRC cachexia could provide a simple survival prediction.