<h3>Purpose/Objective(s)</h3> Malignant obstruction of the major airways is a complicated condition in the ICU, often requiring intubation and endobronchial interventions (EBIs), including stenting and tumor debulking. In cases where EBIs are unavailable or insufficient for respiratory stabilization, the role of radiotherapy (RT) is unknown. RT can reduce tumor burden, but treatment effects are not immediate. In addition, significant resources are required for RT, including costs of treatment and personnel. Our aim was to investigate treatment patterns and benefit of RT in the setting of patients with malignant obstruction requiring intubation. <h3>Materials/Methods</h3> We conducted a single-institution retrospective review at a tertiary care hospital of patients from 2016 – 2022 who underwent RT for a malignant obstruction in the thorax that required intubation and an ICU admission. Demographic information (age, sex, tobacco use, BMI) were collected, along with information regarding histology, staging and prior therapies. Interventions were noted, including EBIs, in-hospital systemic therapy and RT. Relevant dates were observed, including dates of RT, extubation and death. Successful extubation (SE) was defined as extubation for > 48 hours without death or reintubation. <h3>Results</h3> A total of 17 patients received RT for a malignant obstruction that required ICU admission. While only 41% of these patients (7/17) were intubated at the time of the radiation oncology consult, 100% were intubated at some point between the consultation and discharge/death. Dose and fractionation varied significantly, ranging from 5 Gy in 1 fraction to 60 Gy in 30 fractions. Courses with 5 or fewer prescribed fractions were completed in 80% (8/10) of cases, but only 14% of courses (1/7) with more than 5 fractions were completed. Patients did not complete RT due to electing for comfort care or worsening clinical condition that precluded RT. The median survival from RT initiation to death was 15 days for all patients with a maximum of 35 days. Two patients were able to be transferred home prior to death, the remainder died in the hospital. Only 17.6% of patients (3/17) achieved SE. One of these patients was extubated after 2/10 fractions and did not complete RT. The second patient received 17 Gy in 2 fractions and was extubated 3 days after RT completion. The third patient received 25 Gy in 5 fractions, then was extubated 4 days after RT following bronchoscopic debulking. These patients died 5, 5 and 16 days after extubation, respectively. <h3>Conclusion</h3> Intubation due to malignant obstruction carries an extremely poor prognosis when adequate bronchoscopic interventions are not possible. In a small minority of patients, RT may assist in facilitating extubation prior to death, but this outcome is rare. Courses of 5 or fewer fractions are more likely to be completed than courses with more than 5 fractions. Prospective data is merited to more accurately inform patients, physicians and caregivers about the true costs and benefits of RT in this scenario.