Serial chest X-rays of 14 patients with parapneumonic ARDS (PARDS) were analysed retrospectively. Typical findings on chest X-ray films occurred after a latency period of 12-24 h following the clinical start of PARDS. We found some "early signs" of PARDS, such as central interstitial paravascular edema (14/14), bilateral hilar infiltrates (9/14) and the absence of pleural effusion (12/14).