Liver transplantation (LT) may be indicated in cirrhotic patients with underlying pulmonary artery hypertension. However, severe pulmonary artery hypertension with mean pulmonary artery pressure (mPAP) above 50 mmHg has even been considered a contraindication to LT. We present a cirrhotic patient with an mPAP of 56 mmHg measured using right heart catheterization (RHC) and with severely compromised physical capacity. She was first treated with sildenafil (Viagra), a potent novel vasodilator, and successfully transplanted later. The mPAP decreased with sildenafil to the level of 28-31 mmHg and her general condition improved markedly. An LT using piggyback technique was performed 16 weeks later. Despite 2 reoperations for bleeding, the outcome has been excellent. In conclusion, treatment of severe portopulmonary hypertension (PHT) with sildenafil is effective. If a decrease in mPAP is achieved with sildenafil, it may improve the result of LT, even though no evidence of reversibility of PPHTN exists.