The results are presented of the pathological study of the lungs in 66 cases of violent death observing the more frequent types of lesion and establishing 4 different groups of postlesioned pulmonary condition. 1. Inflammatory alveolar lesions without a diffused interstitial involvement (IAL) including contusions or direct aggressions, lobular pneumonias, or bronchopneumonias with a predominance of intra-alveolar inflammatory exudation. 2. Inflammatory alveolar lesions with a diffuse interstitial involvement (IALW) including generalized affectation of the parenchyma with lesions in the capillary structure of the wall. 3. Edemohemorrhagic lesions (EHL) presenting phenomena of capillary congestion with hematic extravasation and interstitial and intra-alveolar edema, without inflammatory involvement. This is the most numerous group and it can constitute the preliminary stage of any other. 4. Unspecific chronic lesions (UCL) not related to the cause of death, being chronically inflammatory and fibrotic alterations of limited interest in our study. We emphasize the importance of the inflammatory involvement of the alveolar wall in the pathogenia of diffuse alveolar damage (DAD) and the aggravation of pulmonary lesions by capillary structure alteration, direct lesions of alveolar epithelium, presence of macrophages, and liberation of certain intracellular enzymes.