Background: Admission of cancer pts in ICU is a medical and ethical challenge, since there is no reliable prognostic tool for guiding decision making. Therefore, recent progress in cancer management improved the OS of advanced cancer pts, rendering this issue more and more frequent. Methods: We have retrospectively analyzed the medical charts of 129 consecutive pts treated in our institution and admitted in ICU from 01/2014 and 04/2019. We identified PF using Cox Models. We analyzed PF for OS or for ability to restart systemic treatment. Results: At the time of ICU admission, the mean age was 58.9 (range, 25-81). The were 51% of men. PS were 0-1 in 61% and 2-3 in 39%. The most prevalent cancers were lung (20%), sarcoma (17%), breast (16%) and gynecological cancers (11%). The number of metastatic sites was 1 (17%), 2 (39%), 3 (26%) and more (19%). The malignancy was stable in 69% and progressive in 31%. Pts currently received systemic treatment in 78%, were free of treatment in 5% and were not yet treated in 16%. Cancer itself (53%), toxicity of treatment (43%) and underlying comorbidities (37%) contributed to ICU admission. The number of organ failures was 0 in 12%, 1 in 40%, 2 in 26% and 3 or more in 22%. The 4 most symptoms were dyspnea (34%), severe infection (25%), cardiac event (23%) and bleeding (10%). Pt management required vasoamines administration (38%), ventilation (31%) and dialysis (4%). The median duration of stay in ICU was 4 days (range, 0-71). 21 (16%) pts died in ICU and 16 (12%) just after ICU discharge. 83 pts returned to home (64%). Systemic treatment was done in 61% of pts who left hospitalization alive after ICU. 1-month, 6-month and 12-month OS were 67, 36 and 21%, respectively. Multivariate analysis identified the following PF for OS: PS = 0 (HR = 0.57 [0.38-0.79]; p = .007), admission related to underlying comorbidity (HR = 0.63 [0.41-0.98], p = .0001) or admission related to treatment toxicity (HR = 0.31 [0.17-0.56] p = .0001). Multivariate identified 1 PF for ability to restart systemic treatment: one or less organ failure (HR = 0.34 [0.14-0.83], p = 0.02). Conclusions: In ICU, OS of adult pts with solid tumors looks like the non-cancer population. ¼ of admitted pts died in ICU or just after. Key PF were PS and cause of critical state. When ICU admission is related to cancer itself, the prognosis was poor.