STUDY OBJECTIVES: Lung transplantation continues to be limited by the development of chronic allograft dysfunction in the form of bronchiolitis obliterans syndrome (BOS). The effect of a transplant operation on patients with BOS has not been well-studied, but patients who undergo double-lung transplantation have better long-term survival. We hypothesized that double-lung transplantation leads to decreased rates of BOS. METHODS: A retrospective review of all lung transplant recipients at our institution, surviving for > 6 months after undergoing their transplant operation. Demographic data, information on other factors leading to the development of BOS, survival information, and data on the presence and timing of BOS were collected. RESULTS: BOS occurred in 41.3% of the recipients (93 of 225 patients) at a median time of 4.2 years. Single-lung transplantation was associated with increased rates of BOS compared to double-lung transplantation (49.3% vs 31.7%, respectively; p = 0.007), at the time of the analysis. Single-lung and double-lung transplant recipients had different baseline characteristics, but after controlling for these factors the type of transplant remained a significant predictor of the length of time to the onset of BOS in a multivariable proportional hazard model. CONCLUSIONS: Double-lung transplantation is associated with a reduced risk for BOS in our study population. A multicenter study with complete BOS information on all patients with a single pretransplant diagnosis would be useful to confirm the above findings. Further research is needed to determine how the type of transplant contributes to the risk for BOS.