<b><i>Background:</i></b> Extracorporeal photochemotherapy (ECP) for chronic lung allograft dysfunction (CLAD) has been reported as beneficial in a few short-term studies. <b><i>Objectives:</i></b> In this retrospective cohort study on 48 CLAD patients treated by ECP (off-line technique) for a period of >8 years (compared to 58 controls), we explored potential predictors of survival and response. <b><i>Methods:</i></b> Failures were defined as a decrease in forced expiratory volume in 1 s (FEV₁) of >10% from ECP initiation. <b><i>Results:</i></b> ECP patients were enrolled between February 2003 and December 2013; 14 (29.2%) with restrictive allograft syndrome (RAS) and 34 with bronchiolitis obliterans syndrome. Grade 1 severity was indicated in 58.3%, grade 2 in 20.8%, and grade 3 in 20.8% of patients. The median follow-up was 65 months (cumulative 2,284.4 person-months). Twenty (41.7%) patients died, including 17 (85%) CLAD-related deaths. Among the controls, there were 42 deaths (72.4%), of which 32 (76.2%) were CLAD related, over a median of 51 months (cumulative 3,066.5 person-months; p = 0.09). Among ECP patients, the FEV₁ slope flattened out after a decline in the initial months (slope -19 ml/month in months 0-6, +4 in months 36-48 and later; p = 0.001). RAS was associated with poorer survival, whereas a ‘rapid decline in the previous 6 months' was not. No ECP side effects or complications were observed. <b><i>Conclusion:</i></b> Long-term ECP for CLAD is safe and reduces FEV₁ decline over time; the RAS phenotype might show a poorer response. ECP deserves to be evaluated in a randomized controlled trial.