Pericardial effusion (PE) is correlated with outcomes in patients with pulmonary arterial hypertension (PAH). Pulmonary artery denervation (PADN) was used for treatment of PAH. The present study aimed to analyze the prognostic value of PE for outcomes after PADN in patients with WHO Group I, Group II and Group IV PAH. PE, frequently seen in patients with connective tissue disease, was featured by fast heart rate, decreased exercise capacity, more syncope, worsening pulmonary arterial hemodynamic and right atrium size. PADN procedure resulted in dramatic reduction of PE. After a median of 376 days follow-up, the rate of PAH-related event, all-cause death and rehospitalization increased over the PE amount and occurred in 29.8%, 19.7% and 25.2% of patients with PE, different to 3.4%, 3.4% and 6.8% of patients without PE ( = 0.034, = 0.041 and = 0.039, respectively). The reduction of PE during follow-up was similar among three groups. Between March 2012 and July 2014, a total of 66 consecutive patients (52 ± 16 years) who underwent PADN were stratified by no PE ( = 20), PE < 10 mm ( = 29) and PE ≥ 10 mm ( = 17) according to baseline echocardiograph. Dynamic change of PE and its correlation with PAH-related event after PADN were measured. PE is associated with increased PAH-related event after PADN. PADN results in significant similar reduction of PE among patients with Group I, Group II and Group IV PAH.