A symptomatic 66-year-old gentleman presented with a large left upper lobe mass, thought likely to be malignant. Further imaging suggested direct tumour extension into the left pulmonary vein. During a subsequent EBUS (endobronchial ultrasound) histological diagnosis was not achieved from sampling higher order lymph nodes, thus intra-procedurally the decision to sample, by Transbronchial Needle Aspiration (TBNA), an area thought to relate to tumour thrombus in the left pulmonary vein was taken. A diagnosis of a non-small cell lung cancer was made on histological testing of the tumour thrombus sample. Considering the bleeding risk, direct probe contact with the endobronchial wall was maintained for several minutes but no bleeding was observed. There were no complications as a result of the procedure. It may be safe to sample tumour thrombus from within a pulmonary vein via EBUS-TBNA to achieve positive histology.