Summary: Sinusitis (rhinosinusitis) is very common disorder, generating a lot of visits both in GP and specialists offices. In the majority of cases, inflammation of the paranasal sinuses (sinusitis) is accompanied by the inflammation of the nasal passages (rhinitis); thus the clinical condition often referred to as „sinusitis” is, in fact, rhinosinusitis and is characterized by the inflammation of the sinuses with concomitant inflammation of the nasal passages. The clinical pattern is characterized by the key symptoms like: nasal blockage and nasal discharge (anterior or posterior – post nasal drip) with facial pain/pressure and impairment/loss of smell (in children – cough). The acute rhinosinusitis (ARS) is characterized by sudden onset and a duration of less than 12 weeks, with a complete resolution of symptoms, whereas the chronic form (CRS) lasts longer than 12 weeks, without complete resolution of symptoms. Acute rhinosinusitis is divided into viral ARS (common cold) and post-viral ARS, which in some cases become bacterial one. Diagnosis is usually based on patient history and physical examination. Specialist consultation is indicated for intractable or complicated disease, signified by signs or symptoms suggestive of orbital, intraosseous, or intracranial extension of sinus disease. Most cases of ARS in the ambulatory setting are viral. In the absence of severe or rapidly worsening symptoms, antibiotic prescription should be delayed until an appropriate surveillance period has elapsed. Symptomatic therapy is the most efficient approach for uncomplicated ARS. There is a paucity of data supporting use of commonly used symptomatic therapies, with the exception of intranasal corticosteroids, which have demonstrated rapid improvement of the symptoms of ARS and return to normal functioning when used as monotherapy or as an adjunct to antibiotics. Also phytotherapy shows some efficacy, especially with the latest herbal drug combination and nasal saline irrigation. CRS may manifest as one of three major clinical syndromes: CRS without nasal polyps, CRS with nasal polyps, or allergic fungal rhinosinusitis. These classifications possess a great deal of therapeutic significance. Chronic sinusitis may result from incorrectly treated recurrent acute rhinosinusitis, may be related to allergy, cystic fibrosis, gastroesophageal reflux, or exposure to environmental pollutants. Allergic rhinitis, nonallergic rhinitis, anatomic obstruction in the ostiomeatal complex, and immunologic (and autoimmunologic) disorders, as well as intolerance of nonsteroidal anti-inflammatory drugs are known risk factors for chronic sinusitis. Medical therapy, mainly intranasal steroids, is directed toward controlling predisposing factors, treating concomitant infections, reducing edema of sinus tissues, and facilitating the drainage of sinus secretions. The goal in surgical treatment, which is particularly dedicated to ENT specialist, is to reestablish sinus ventilation and to correct mucosal pathology in order to restore the mucociliary clearance system. Surgery strives to restore the functional integrity of the inflamed mucosal lining. In some cases unfortunately, despite the appropriate treatment we observe, so called: rhinosinusitis difficult-to-treat.