Chronic rhinosinusitis is hypothesised to play a major role in lung transplant recipients with cystic fibrosis. Paranasal sinuses are considered to accumulate a significant bacterial load, potentially leading to lung allograft infection with ensuing complications such as bronchiolitis obliterans syndrome, i.e. allograft rejection. We therefore would like to present our combined medical and surgical treatment plan, which consists of an endoscopic fronto-spheno-ethmoidectomy as well as a meticulous daily nasal care program. The microbiological results show that our combined concept is effective, whereas especially daily nasal care with isotonic saline solution is the cornerstone in preventing significant colonisation of the sinuses and spreading bacteria to the lower respiratory tract causing lung allograft infection. Regarding the surgical part of our treatment, it should be emphasised that all sinuses and ethmoidal air cells should be widely opened. Edges such as bony overhangs should be smoothened to avoid mucus retention and consecutive bacterial recolonisation requiring subsequent revision surgery.