Aims: To study the effect of radiofrequency thermocoagulation (RFT) of the sphenopalatine ganglion (SPG) on headache and facial pain conditions following critical reevaluation of the original diagnosis. Methods: This was a retrospective study of clinical records gathered over 4 consecutive years of all 15 facial pain or headache patients who underwent RFT of the SPG at a tertiary pain clinic; diagnoses were reevaluated, after which the effect of RFT on facial pain was assessed. Results: After application of new criteria for Sluder's neuralgia (SN) and strict criteria for cluster headache (CH), seven patients out of the 15 turned out to have been diagnosed correctly. Nine of the 15 patients showed considerable pain relief after RFT of the SPG. Positive results were most frequent among patients with Sluder's neuropathy, atypical facial pain, and CH. However, repeated RFT procedures were needed in most patients. Conclusion: Correct headache and facial pain diagnosis is vital to assess the outcome of different treatment strategies. Even in a tertiary center, headache and facial pain can be misdiagnosed. RFT of the SPG may be effective in patients with facial pain, but repeated procedures are often needed. Schlagwörter: atypical facial pain, classification, cluster headache, facial pain, radiofrequency thermocoagulation, Sluder's neuralgia