Continuing advances in PET imaging have resulted in an improved ability to evaluate thoracic malignancies. Published reports demonstrate that PET provides accurate, non-invasive detection and staging of thoracic malignancy. Preliminary studies suggest that PET may also be able to assess the therapeutic response accurately. The studies investigating PET have been relatively small but have shown statistically significant advantages over conventional non-invasive techniques in accuracy and possibly even cost/benefit performance in thoracic malignancies.