BACKGROUND: With the event of angled endoscopes, image guidance and the rapidly improving endoscopic techniques the previously used osteoplastic frontal sinus fat obliteration (ISO) becomes more and more a second line treatment option. The objective of our study is to describe the up-to-date indications for FSO based on our own experience. METHODS: Retrospective analysis including follow-up visits of 77 patients with frontal sinus fat obliteration at our clinic between 1991 and 2006 was undertaken and descriptive statistics were drawn. RESULTS: Thirty-six cases were operated by FSO as a first-line treatment, 41 had previous surgery. Eighty percent of all patients showed no postoperative residual complaints. Two patients required revision surgery. General complication rate was 36.4%, however these consisted in the vast majority of cases (90%) of minor complications. CONCLUSIONS: FSO still remains a valuable operation for specific indications. FSO is the gold standard for repeatedly failed endoscopic procedures. The operation should also target the following indications as a first-line treatment: large/lateral osteomas, malignant disease, lateral mucoeceles, most fractures of the posterior sinus wall with CSF-leak, osteomyelitis, pathologies in small underdeveloped sinuses with narrow floor. It is associated with minimal complications and a good outcome.