Cystic fibrosis (CF) lung disease is caused by mutations in the CFTR-gene and remains one of the most frequent lethal inherited diseases in the Caucasian population. Given the progress in CF therapy and the consecutive improvement in prognosis, monitoring of disease progression and effectiveness of therapeutic interventions with repeated imaging of the CF lung plays an increasingly important role. So far, the chest radiograph has been the most widely used imaging modality to monitor morphological changes in the CF lung. CT is the gold standard for assessment of morphological changes of airways and lung parenchyma. Considering the necessity of life-long repeated imaging studies, the cumulative radiation doses reached with CT is problematic for CF patients. A sensitive, non-invasive and quantitative technique without radiation exposure is warranted for monitoring of disease activity. In previous studies, MRI proved to be comparable to CT regarding the detection of morphological changes in the CF lung without using ionising radiation. Furthermore, MRI was shown to be superior to CT regarding assessment of functional changes of the lung. This review presents the typical morphological and functional MR imaging findings with respect to MR-based follow-up of CF lung disease. MRI offers a variety of techniques for morphological and functional imaging of the CF lung. Using this radiation free technique short- and long-term follow-up studies are possible enabling an individualised guidance of the therapy.