Ruxolitinib, a selective Janus kinase (JAK)1/2 inhibitor, has recently been proposed for steroid refractory chronic graft-versus host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT), particularly in severe skin cGVHD. Lung function impairment is common in severe skin cGVHD through concomitant bronchiolitis obliterans syndrome (BOS) or restrictive lung disease (RLD) from skin sclerosis. No treatment to date has shown benefit on lung function in this context. We retrospectively assessed the effect of ruxolitinib on lung function in a cohort of patients treated for sclerotic-type skin cGVHD. Between March 2015 and April 2018, 70 patients were diagnosed with sclerotic-type skin cGVHD. Amongst those, 36 received ruxolitinib. To handle confounding by indication bias, exposure groups were matched on the propensity score to receive ruxolitinib incorporating age, myeloablative conditioning, total body irradiation, bronchiolitis obliterans (BOS), forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and tobacco at the time of cohort entry, as well as the time from transplantation. Matching 1:1 used a greedy-matching algorithm with replacement, using a caliper of 0.10.  We compared both FVC and FEV1 trajectories during the follow-up on the matched samples, using linear mixed effects models. Median follow-up of the 46 matched patients was 58 months (IQR, 32 to 84). Ten patients had a RLD (6 exposed; 4 unexposed) while 13 patients were diagnosed with BOS (8 exposed, 5 unexposed). FEV1 significantly decreased over time independently of exposure to ruxolitinib (p<0.0001). FEV1 trajectory was similar in exposed and unexposed patients (p= 0.11). In conclusion, ruxolitinib administration did not demonstrate any improvement in the course of respiratory function in allogeneic HSCT recipients with sclerotic-type skin cGVHD.Copyright © 2020. Published by Elsevier Inc.