Virtual assisted lung mapping (VAL-MAP) is a new technique for bronchoscopic lung marking developed to assist in navigational lung resection. Unlike conventional marking techniques using a single marking to identify an intrapulmonary tumor, VAL-MAP utilizes multiple dye-mediated markings, providing “geometric information” on the lung surface. The purpose of the technique is to identify a tumor and obtain sufficient resection margins, either in wedge resection or segmentectomies. Computer-based virtual bronchoscopy is used to design the lung map and to identify target bronchi for each marking. The dye injection procedure is conducted using a regular bronchoscope under fluoroscopy followed by a CT scan, which is then reconstructed into 3D images for intraoperative navigation. The advantages of VAL-MAP include: it is a reasonably safe procedure based on experience from approximately 1,300 markings undertaken in >430 patients; the dye lasts without significant fading for 2–3 days; the technique has good reproducibility; and multiple markings and adjustment using post-mapping CT result in the procedure being highly resistant to technical failure. VAL-MAP is likely to benefit many patients and surgeons in the era of minimally invasive navigational-based thoracic surgery. The technique has scope for further development, making it an exciting new field of research in thoracic surgery.