Cystic fibrosis (CF) is a progressive genetic disorder with an autosomal recessive inheritance pattern. The condition is characterized by ongoing infections in the lungs and continuous aggregation of thick mucus secretion. Chronic rhinosinusitis (CRS) is extremely common in CF patients, with an incidence rate approaching 100%. Further, CF is the most common cause of nasal polyposis in the paediatric population. Considering this, checking of all children who present with polyps for CF is strongly recommended. Typically, CF related CRS (CF-CRS) is resistant to conservative therapy, frequently necessitating more invasive interventions. Endoscopic sinus surgery (FESS) is an effective and safe treatment modality that reliably improves quality of life in both adults and children with CRS. Maxillary mega-antrostomies are typically recommended for CF-CRS cases, given the high need for follow-up surgeries and to aid post-operative lavage. There is some evidence indicating the utility of FESS for asymptomatic CF-CRS patients too, as this could help eradicate potential pathogens in the maxillary sinuses.