Introduction: A 53-year-old female presented with a large (945 cc) unresectable leiomyosarcoma of the uterus, with metastasis in the lungs, significant abdominal/pelvic pain and evidence of hydronephrosis secondary to obstruction caused by the mass. In an effort to palliate symptoms, radiation was recommended.Methods: Given the size of the lesion, the patient was treated with crossfire GRID, a type of spatially fractionated radiotherapy (18 Gy x 1), followed four weeks later by a short course of external beam radiation (4 Gy x 5).Results: The patient experienced significant symptom relief. Her abdominal/pelvic pain resolved, and a stent was placed to relieve her hydronephrosis. The tumour volume had decreased significantly (5 center dot 5 months post-treatment 276 cc, 8 center dot 5 months post-treatment 17 cc). Unfortunately, at 9 months post-treatment, the patient died from progression of her metastatic disease in the lungs.Conclusions: The use of GRID radiotherapy resulted in effective and sustained palliation of a large uterine leiomyosarcoma in this patient's case.