The patient investigated was a 43-year-old woman with primary pulmonary hypertension (PPH) and refractory protein-losing enteropathy (PLE). She underwent living-donor lobar lung transplantation (LDLLT), which led to remarkable improvement in both pulmonary hypertension and PLE. Although there have been no reports, to our knowledge, that have demonstrated PLE as a complication of PPH, the present case clearly shows how PLE could complicate PPH. In addition, and more importantly, hypo-proteinemia due to PLE should not necessarily be an exclusion criterion for lung transplantation when PPH is involved, because it could markedly improve after transplantation.