Background: Invasive mechanical ventilation (IMV), dialysis for acute kidney failure, and other critical care therapies (CCTs) are associated with a high risk for complications in patients with metastatic cancer. Inpatient palliative care (IPC) can assist in assessing patients' preferences for life-prolonging treatment at the end of life. This study investigated the use pattern of IPC, outcomes (in-hospital mortality, length of stay [LOS], discharge destination, and cost of care), and predictors of IPC use in patients with metastatic cancer who received CCTs. We hypothesized that IPC services are underused in this cohort. Methods: In this retrospective cohort study, we used the 2010 California State Inpatient Databases to identify adults with metastatic cancer who received CCTs that are common and reliably coded (IMV, tracheostomy, percutaneous endoscopic gastrostomy tube, dialysis for acute kidney failure, and total parenteral nutrition). We determined IPC use in all patients, in those who received IMV, and across 4 cancer subtypes (lung, breast, colorectal, and genitourinary). Outcomes were assessed based on IPC use. Multivariable analyses were used to investigate factors associated with IPC use. Results: We identified 5,862 hospitalizations, 19.8% of which used IPC services. IPC use varied across cancer subtypes (lung, 28.3%; breast, 22.4%; colorectal, 12.8%; genitourinary, 16.1%; P<.01). Patients who received and did not receive IPC services had high in-hospital mortality rates (63.9% and 29.8%, respectively), and costs of care and LOS were lower in survivors who received IPC compared with those who did not. Predictors of IPC use were lung cancer (vs colorectal or genitourinary cancer), higher comorbidity score, do-not-resuscitate status on admission or within 24 hours of admission, infections (vs cancer-related diagnoses), and higher hospital bed count. Conclusions: Use of IPC was low in the cohort who received CCTs with poor outcomes, although data on outpatient palliative care services is lacking. Predictors of IPC use may be used to identify patients who may benefit from these services.