Introduction: Organ transplant recipients might be more likely to develop COVID-19, as they receive long-term immunosuppressives and have comorbidities. Case Presentation: Herein, we reported the case of a 32-year-old man with unilateral lung transplantation due to unclassifiable lung fibrosis on pathologic evaluation who presented with cough, fever, and headache. After evaluation with RT-PCR test and chest CT scan, COVID-19 in the previously transplanted lung was diagnosed. However, the other non-transplanted fibrotic lung was not involved. Conclusions: Lack of COVID-19 involvement in the fibrotic lung tissue in our case without any other risk factors might be related to the fact that the lung with underlying diseases was less susceptible to COVID-19 as unhealthy lungs have lower ACE2 receptors, or it might be related to genetic differences between the donor and recipient