Sinoscopy consists on direct visualization of the paranasal sinuses and was first conceived for diagnostic purposes using an endoscope through a skull trephination. Since then, the use and approaches to perform it have evolved thanks to current advancements in knowledge (sinus anatomy and pathology) and technology. The aim of this study is to review the techniques reported to perform traditional and minimally invasive sinoscopy and to review the current use of sinoscopy to treat paranasal sinus disease. The history of sinoscopy, as we know it today, is relatively recent but its use among clinicians is not necessarily widespread due to the invasiveness of the traditional technique when compared to imaging techniques. This limitation could be bypassed using the newer intranasal or extranasal minimally invasive sinoscopic approaches. These techniques allowed sinoscopic visualization through natural orifices or minimally invasively created openings. Despite the potential of these techniques, case selection is still crucial as visualization can be limited in selected pathologies (i.e: sinus cyst), some sinuses (i.e: rostral maxillary with intranasal approaches) and if haemorraghe or severe exudate accumulation is found. Nevertheless, sinoscopy offers a diagnostic rate superior to traditional imaging and it is an alternative diagnostic tool when advanced imaging techniques, such as CT, are not available. In recent years, sinoscopic treatment is progressively replacing the use of sinusotomies to treat most sinus pathologies. Sinoscopic treatment yields a high resolution rate while complications are kept low. Familiarization with sinoscopic techniques and in-depth anatomic sinus knowledge will likely make sinoscopy the gold standard technique to treat sinus disease in the short future.