Objective: A study is made of the clinical course of patients with episodic cluster headache following the injection of corticosteroids in the proximity of the sphenopalatine ganglion of the affected side. Study Design: A retrospective observation study was made corresponding to the period between 2006 and 2010. Patients with episodic cluster headache received corticosteroid infiltrations in the vicinity of the sphenopalatine ganglion. Data were collected to assess the clinical course, quantifying pain intensity and quality of life. A total of 23 patients (11 women and 12 men) with a mean age of 50.4 years (range 25-65) were included. Forty percent of the patients had undergone dental extractions in the quadrant affected by the pain, before the development of episodic cluster headache, and 37.8% underwent extractions in the same quadrant after appearance of the headache. Results: Most of the patients suffered 1-3 attacks a day, with a duration of pain of between 31-90 minutes. The mean pain intensity score during the attacks at the time of the first visit was 8.8 (range 6-10), versus 5.4 (range 3-9) one week after the first corticosteroid injection. On the first visit, 86.9% of the patients reported unbearable pain, versus 21.7% after one week, and a single patient after one month. Conclusions: The evolution of episodic cluster headache is unpredictable and variable, though corticosteroid administration clearly reduces the attacks and their duration.