The study is based upon 80 patients, suspected of having recurrent laryngeal cancer, who underwent an 18F-FDG PET study on a coincidence camera and a laryngoscopic biopsy under general anaesthesia. The potential value of 18F-FDG PET in the detection of local relapses of laryngeal cancer after radiotherapy by use of a coincidence camera was prospectively assessed, and a cost-effectiveness analysis was performed retrospectively. The effectiveness of 18F-FDG PET is reflected in sensitivity and specificity, positive predictive value (PPV) and negative predictive value (NPV) using comparison with the biopsy results as a gold standard. In case of a negative biopsy result, follow-up was continued for a minimum of one year. The results showed a sensitivity of 100%, a specificity of 85%, a PPV of 87%, and a NPV of 100%. Costs per patient of a 18F-FDG PET scan were 682 euro, whereas the saved costs by reducing CT-scans and panendoscopies were 618 euro. In this scenario implementation of 18F-FDG PET scintigraphy in the detection of recurrent laryngeal cancer has additional costs of 64 euro per patient. However, panendoscopy related complications, and potential improvement in quality of life due to early detection of recurrent disease were not taken into account in this study. In conclusion, the technical efficacy of 18F-FDG PET in the detection of recurrent laryngeal cancer is high. 18F-FDG PET is more accurate than CT, and in addition the cost-effectiveness ratio of 18F-FDG PET lies within an acceptable range and has further improvement potential when a quality of life factor is included in a prospective cost-effectiveness analysis.