In the past, the sphenoid sinus has often been overlooked. It was considered as an inaccessible paranasal sinus cavity due to its specific anatomical location, making it difficult to diagnose diseases.Today, the sphenoid sinus is regarded as equal to any other paranasal sinus cavity, and thus home to various diseases. Over the years, the assessment of these diseases has improved. Indeed, nasal endoscopy and qualitative head imaging (CT-scan and MRI) have been developed. These technologies provide information about the nature of disease, about the state of the walls of the sphenoid sinus and about extension of a lesion to adjacent structures. The endoscopic endonasal approach has improved safety and efficacy of sphenoid sinus surgery. Moreover, the sphenoid sinus acts as a gateway to the skull base. In fact, it enables removal of sellar and parasellar lesions. This endoscopic endonasal transsphenoidal approach (EETA) has lower morbidity rates than transcranial approaches.The authors propose an overview of the sphenoid sinus from an ENT point of view.