Aims: Inadequate surgical frontal sinus drainage in chronic sinusitis cases refractory to conservative treatment results in a poor clinical response and is associated with recurrent frontal recess stenosis. Endonasal frontal sinus drainage procedures are classified according to Draf into three groups: DrafIIb enables unilateral orbit to septum drainage and the IIc is the extension of the IIb across the midline. The purpose of our report is to review chronic sinusitis cases treated at our Department using the standard (IIb) or modified (IIc) procedure and compare results. Methods: Patient- and surgery-related data were retrieved on patients operated between 2013 and 2016 for chronic frontal sinusitis using the standard/modified DrafIIb procedure.The modified IIb (i.e. IIc) procedure was performed so that both frontal sinus ostia were visualized by performing an intersinusseptectomy: the aim was to provide drainage to both frontal sinuses simultaneously. Results: In the observed period, 26 patients were treated: 12 using the modified DrafIIb (IIc) and 14 using the standard DrafIIb procedure. There were no significant differences between groups regarding age, sex, number of previous procedures or follow-up period. All patients had an uneventful postoperative recovery and there were no cases of re-stenosis observed in the DrafIIc group; there were seven cases of restenosis in the DrafIIb group.