The identification of fatal mechanisms involving drowning represents a difficult task for the forensic pathologists. Here, we analysed macromorphological, histopathological and microbiological findings that influence the lung weight of drowning. Then, we also tried to characterize drowning victims with low-weight lungs. Following exclusion criteria, of the 78 drowning cases finally selected, 18% exhibited a lung weight lower than 1000 g. Higher lung weights, mainly found in males, younger subjects and bodies found in seawater than freshwater, were correlated with external and tracheobronchial foam and alveolar macrophages. In males, pulmonary oedema was associated with higher lung weight but alveolar oedema was related to lower lung weight. Following exclusion criteria and microscopic findings (alveolar oedema and diatoms) we could identify a 3.8% of drowning cases with lungs weighting less than 1000 g. These results could help us to characterise cases of drowning as a consequence of a profound asphyxiation without liquid aspiration.