Cases of benign isolated lesions of the sphenoid sinus are rare. For descriptive purposes, clinicians divide them into inflammatory and non-inflammatory with prevalence of the former. Symptoms of the sphenoid sinus disease are difficult to characterise, the most common of them being vague headache and visual disturbances. Thorough preoperative evaluation of the lesion is essential - nasal endoscopy must be performed and computerised tomography or magnetic resonance imaging results analysed. The purpose of the study is to present the assessment of endoscopic surgery outcome in the group of patients with isolated benign sphenoid disease. Clinical data of 21 subjects were analysed retrospectively. Female to male ratio is 2:1 with age range between 12 & 58 years old. There were 10 patients with bacterial sinusitis, 6 with fungal sinusitis, 2 with allergic thickening of the mucous membrane with no evidence of bacterial or fungal infection, 2 with mucocele, and 1 with cerebrospinal fluid fistula. Each patient had preoperative nasal endoscopy and CT/MRI imaging performed. Then they underwent endoscopic transnasal sphenoidotomy with removal of the lesion or closure of the fistula. The sphenoid sinus was approached through its front wall. The patients' postoperative course was uneventful. They noted improvement in all preoperative symptoms.