Rapamycin (RAPA) is a powerful immunosuppressant that also acts as an antiproliferative, which, therefore, could be useful in the treatment and prevention of bronchiolitis obliterans (BOS) in lung transplant recipients. We sought to report our experiences with RAPA in lung transplant patients with BOS that has not responded to the administration of other drugs.We performed a retrospective analysis of the clinical characteristics, pulmonary function, and complications among patients with BOS who received RAPA.RAPA was administered to 11 patients, three single-lung transplant and eight bilateral lung transplant recipients, of whom five were women and six men, of mean age 48 years (26 to 65). The median posttransplant time to the initiation of RAPA for progressive BOS was 32 months (4 to 69) with a posttreatment follow-up of 15 months (3 to 34). RAPA was administered to all patients in association with a calcineurin inhibitor (tacrolimus in seven cases, and cyclosporine in four and steroids. Eight of the 11 patients (72%) with progressive deterioration of pulmonary function showed improved and/or stabilized FEV1 figures after introduction of RAPA. Eight patients developed adverse effects, which were possibly related to RAPA, leading to treatment withdrawal in two cases. The most frequent adverse effects were infections among 6 of the 12 cases, and myelosuppression in three.RAPA may be useful to stabilize or improve pulmonary function in patients with BOS. Nevertheless, it was necessary for patients to be closely monitored so that possible adverse effects, and especially infections, may be detected early.