Background There has been little study on the variability of CsA pharmacokinetics in stable lung transplant (LT) recipients without cystic fibrosis. This study was conducted to determine the prevalence of high intra-individual variability of CsA in LT recipients and its implications in CsA monitoring. Methods Twenty-nine pharmacokinetic curves were performed in 10 consecutive stable patients from a single center. The intra-individual coefficient of variation (CV) of the AUC0–12 h was calculated in each case. Patients were grouped according to whether their CV was high (≥20%) or low (