Background- Superior Vena Cava Syndrome (SVCS) is a life-threatening oncological emergency affecting children with T-cell Acute lymphoblastic Leukemia (T-ALL)/ T-Lymphoblastic Lymphoma (T-LBL). This can prove fatal if not managed appropriately and promptly. Method- We describe critical care needs and outcome of T-ALL/T-LBL patients managed in our unit from 1 ^st May 2016 to 31 ^st March 2021. Result- Twenty-three of the 120 pediatric ALL/LBL patients (19%) managed in our unit had T-ALL/T-LBL. Eleven (48%) patients presented with SVCS. All presented with cough and dyspnea. Chest X-Ray showed mediastinal widening in all patients. Flow cytometry in various body fluids could reach prompt diagnosis in 90% patients and mass biopsy was performed in only 1 patient. Eight patients required Pediatric Intensive Care Unit support. All 11 patients were started on corticosteroids soon after diagnosis of SVCS. The median time to symptom relief was 4 days and that for significant improvement on X-ray was 7days. At a median follow up of 23-months (6-63 months) overall survival and event-free survival was 75%. Conclusion- T-ALL/T-LBL patients with SVCS with good critical care can have improved outcomes. Prompt therapeutic interventions like pericardiocentesis can be life-saving. Flow cytometry can be a handy tool for quick diagnosis and help avoid invasive procedures in sick patients.