Cystic fibrosis (CF) is a life-threatening autosomal recessive multi-organ disorder with the mean incidence of 0.737 per 10,000 people worldwide. Despite many advances in therapy, patients fail to have a satisfactory quality of life. The end-stage lung disease still accounts for significant mortality and puts patients in the need of lung transplantation. Even though the disease is monogenic, the trials of topical gene transfer into airway epithelial cells have so far been disappointing. It is proven that stem cells can be differentiated into type II alveolar epithelial cells. Wharton's jelly-derived mesenchymal stem cells (MSC) from non-CF carrier third-party donors could be an effective alternative to bone marrow or embryonic stem cells. The harvesting process is an easy and ethically uncontroversial procedure. The MSC cell should be applied through repetitive infusions due to rapid lung epithelial cell turnover. However, the low stem cell incorporation remains a problem. Pre-clinical studies imply that even 6-10% of the wild-type cystic fibrosis transmembrane conductance regulator (CFTR) expression could be enough to restore chloride secretion. The route of administration, the optimal dose, as well as the intervals between infusions have yet to be determined. This review discusses the clinical potential of mesenchymal stem cell in CF patients.