Achilles tendonitis or rupture are uncommon complications following the use of fluoroquinolones, with a reported incidence in the general population of 0.4%. The aims of the current study were to determine the incidence of Achilles tendon disease (ATD) in lung transplant recipients (LTR) and to identify risk factors. Questionnaires were sent to 150 LTR of whom 101 responded (67%). Twenty-two LTR (21.8%) experienced ATD (tendonitis 16, rupture six). The mean age of LTR who developed ATD was 52.9+/-6.1 yrs (range: 19-63.5 yrs). Only the use of ciprofloxacin was significantly associated with ATD (p<0.05). Age, sex, underlying disease necessitating transplantation, serum creatinine and cyclosporine levels were not associated with ATD. The association between ciprofloxacin and ATD was not dose related. Of the 72 LTR who had received ciprofloxacin, 20 (28%) developed ATD (tendonitis 15, rupture five). In patients receiving ciprofloxacin, there was no association between the mean cumulative dose of prednisolone and ATD. Tendon rupture occurred with a lower ciprofloxacin dosage than tendonitis and the mean recovery duration was significantly longer. To conclude, lung transplant recipients receiving ciprofloxacin are at significant risk of developing Achilles tendon disease. The association between ciprofloxacin and Achilles tendon disease appears to be idiosyncratic rather than dose-related.