In cystic fibrosis (CF), chronic airway infection and neutrophil-dominated airway inflammation lead to progressive lung disease. Cytokines play an important role in the inflammatory response. Evidence suggests that cytokine production is altered or dysregulated in CF. Moreover, polymorphisms in cytokines may be linked to disease severity by acting as modifier genes. This article reviews the current state of knowledge regarding individual cytokines and CF lung disease, with an eye towards the possibility that cytokines may be used as outcome measures in clinical trials in CF. In addition, cytokines may eventually serve as targets for novel anti-inflammatory therapies in CF.