Background Survival after idiopathic pulmonary arterial hypertension (IPAH) diagnosis is often shorter than the waiting time for grafts. Iloprost and bosentan improve outcome in advanced IPAH (New York Heart Association Functional Class III), but there is controversy about the limits of their efficacy in end-stage (Class IV) IPAH. Methods We investigated the impact of iloprost (prostacyclin analog) and bosentan (endothelin-receptor antagonist) therapy on the outcome of patients with IPAH after listing for transplantation (Tx) to answer the following questions: (1) How efficient is this treatment in reducing mortality on waiting lists? (2) Is Tx still most promising for survival once recurrent right heart failure emerges, or can this treatment improve survival to an extent that exceeds post-Tx survival? We assessed the outcome of our IPAH patients listed for Tx between September 1996 and September 2005 in relation to kind and duration of medical treatment. Results Among 59 listed patients, 24 (40.7%) died before Tx, after 2.9 months (median). With iloprost and/or bosentan treatment the mortality on Tx lists was 33.3%, whereas with calcium-channel blockers it reached 64.3% ( p < 0.05). Patients with iloprost and/or bosentan therapy showed similar survival, regardless of whether they responded to vasodilator testing. Survival after listing was better for patients who were transplanted than for those who received iloprost and/or bosentan but not Tx ( p = 0.017). Iloprost and bosentan treatment allowed the withdrawal of 3 patients from Tx lists. Conclusions Iloprost and bosentan allowed the effective bridge-to-transplant treatment in IPAH. However, with this treatment the mortality rate on Tx lists remained high and survival benefit was lower than from transplantation.