Résumé : Introduction: Pericardial effusion is a potentially fatal complication of malignant tumors. Over the past few decades, cancer therapies and the management of pericardial effusions have evolved. Our study aims to determine the predictive factors of in-hospital mortality following pericardial effusion in oncology patients admitted to the intensive care unit (ICU). Materials and Methods: All medical records of oncology patients who experienced pericardial effusion requiring admission to the ICU at the Jules Bordet Institute between January 2004 and December 2021 were retrospectively analyzed. Univariate and multivariate analyses were performed to establish the predictive factors of in-hospital mortality. Results: 119 pericardial effusions requiring ICU admission occurred in 111 cancer patients during the study period. Fifty-four patients had lung cancer, 21 had breast cancer, 18 had hematological cancer, and 18 had other solid tumors. The majority of pericardial effusions were treated with a pericardial window. Six patients experienced one or more recurrences requiring readmission to the ICU. The in-hospital mortality rate was 24%. In multivariate analysis, three factors were statistically associated with higher mortality: age (≥60 years), malignant etiology, and the presence of lower limb edema. Median survival was 6 months. Conclusion: In cancer patients with pericardial effusion requiring ICU admission, the in-hospital mortality rate was 24%, and its predictive factors were age (≥60 years), malignant etiology, and the presence of lower limb edema.