Résumé : Objectives: Early intensive care unit (ICU) admission, in Critically Ill Cancer Patients (CICP), is believed to have contributed to the prognostic improvement of critically ill cancer patients. The primary objective of this study was to assess the association between early ICU admission and hospital mortality in CICP. Design: Retrospective analysis of a prospective multicenter dataset. Early admission was defined as admission in the ICU < 24 h of hospital admission. We assessed the association between early ICU admission and hospital mortality in CICP via survival analysis and propensity score matching. Results: Of the 1011patients in our cohort, 1005 had data available regarding ICU admission timing and were included. Overall, early ICU admission occurred in 455 patients (45.3%). Crude hospital mortality in patients with early and delayed ICU admission was 33.6% (n = 153) vs. 43.1% (n = 237), respectively (P = 0.02). After adjustment for confounders, early compared to late ICU admission was not associated with hospital mortality (HR 0.92; 95%CI 0.76–1.11). After propensity score matching, hospital mortality did not differ between patients with early (35.2%) and late (40.6%) ICU admission (P = 0.13). In the matched cohort, early ICU admission was not associated with mortality after adjustment on SOFA score (HR 0.89; 95%CI 0.71–1.12). Similar results were obtained after adjustment for center effect. Conclusion: In this cohort, early ICU admission was not associated with a better outcome after adjustment for confounder and center effect. The uncertainty with regard to the beneficial effect of early ICU on hospital mortality suggests the need for an interventional study.