Right ventricular (RV) failure is a leading cause of mortality in patients with pulmonary arterial hypertension (PAH). However, up to 25% of such patients die unexpectedly, without warning signs of hemodynamic decompensation.We previously documented that pulmonary artery (PA) dilatation significantly increases the risk of those deaths.4Some of them may be due to dissection of PA resulting in cardiac tamponade. Confirmation that pulmonary dissection may be one of the causes of unexpected death in PAH is difficult, as by definition, most of those deaths occur outside hospitals. On the other hand, dissection does not always lead to immediate death. Out of 63 cases of dissections of PA collected by Khattar et al. based on reports published up to 2003, eight have been diagnosed ante-mortem.We present four patients with severe PAH and PA dilatation in whom PA dissection has been confirmed. This represents 1.6% of 249 patients diagnosed with PAH during 1998–2009 and subsequently followed by our team.Based on this series, we try to identify clinical patterns which might indicate impending dissection. We also highlight individual differences in clinical presentation and outcome of PA dissection in PAH and discuss the available management strategies as well as challenges for the future.