We present the case of an asymptomatic 60 year old man with an incidental finding of a tumour lying adjacent to the superior vena cava on echocardiography. Duplex ultrasonography and CT scanning demonstrated a tumour lying adjacent to the subclavian vein as well as within the superior vena cava. At operation a lipoma was found lying adjacent to the subclavian vein. This passed within the vein lumen more proximally. The tumour was successfully removed and all major veins remained patent at follow-up one month later. Histological examination confirmed that the tumour was lipoma without evidence of malignant change.