Introduction and objective: Paediatric chronic rhinosinusitis (PCRS) is a common disease in children. It is defined as an ongoing inflammation of the nasal cavity and sinuses lasting for over 12 weeks. Due to prevalence in the population, PCRS is associated with a high healthcare and financial burden. During the examination, attention should be paid to symptoms that may suggest chronic rhinosinusitis (CRS), because it may be underdiagnosed. Due to the chronicity of the inflammatory process and the similarity of symptoms to allergic rhinitis and adenoid hypertrophy, diagnosis and treatment are difficult. In this review, guidelines from The European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020 and recent literature reports from Medline and Scopus database are analysed. Review methods: Information was obtained through a review and analysis of the PubMed Medline and Scopus databases. Brief description of the state of knowledge: Diagnostic difficulties with CRS can be caused by many factors. The EPOS guidelines recommend flexible or rigid nasal endoscopy as a preliminary objective method to assist in the recognition of CRS. Computed tomography (CT) is not recommended for routine management; therefore, CT is the gold standard for imaging when establishing a PCRS diagnosis or preparing for sinus surgery. The use of conventional X-ray imaging for chronic rhinosinusitis is limited and not recommended. Conclusions: Understanding the symptoms of chronic rhinosinusitis is of utmost importance in daily practice. Early initial assessment of symptoms in children with a high probability of CRS allows for early diagnosis and reduces the need for endoscopic and imaging examination.