Objective To investigate the effect of prone position ventilation (PPV) on hemodynamics in patients with interstitial lung disease (ILD) concurrent with acute respiratory distress syndrome (ARDS) or not. Methods Severe ARDS patients received PPV treatment in intensive care unit from 2013 to 2015 were retrospectively analyzed. Pulse index continuous cardiac output (PiCCO) monitoring indices were compared 2h before PPV (PPV-2), in-PPV (PPVmean) and 2h after turn back to supine position (PPV+2), including mean arterial pressure (MAP), cardiac index (CI), intrathoracic blood volume index (ITBVI), etc. Heart function, liver function, renal function, coagulative function were compared before and after all the PPV treatment. Results Thirty-six severe pulmonary ARDS patients were recruited. Norepinephrine (NE) dose was (0.14±0.10) μg·kg-1·min-1 and lactate concentration was (1.70±0.57) mmol/L before PPV. CI in all the patients was increased [(4.06±0.95) L·min-1·m-2 vs. (3.98±1.05) L·min-1·m-2, P > 0.05) and central venous oxygen saturation, ITBVI [(76.94±8.94)% vs. (70.67±8.23)%, (982.17±245.87) mL/m2 vs. (912.97±177.65) mL/m2, P < 0.05)] were significantly increased compared with PPV-2, while heart rate (HR), MAP, urine volume were decreased (P > 0.05). The patients were divided into an ILD group (n=17) andanon-ILD group (n=19),and no significant differences were found in baseline data between two groups. Compared with PPV-2, MAP was significant decreased at PPV+2 [(85.44±10.84) mm Hg vs. (89.21±10.92) mm Hg, P < 0.05) in the ILD group. Compared with PPVmean, CI was obviously declined at PPV+2 in the ILD group. Activated partial thromboplastin time was increased [(67.04±97.52)s vs. (41.24±8.72) s, P < 0.05] and BUN was higher [(10.64±4.95) μmol/L vs. (8.18±3.88) μmol/L, P < 0.05] in the ILD group, while no significant difference was found in the non-ILD group. Conclusion PPV will not affect cardiac output in severe ARDS patients with ILD. It can increase venous return and improve tissue perfusion, but the perfusion of the abdomen organ need to be monitored cautiously.