The diagnosis of drowning relies primarily on critical examination of the subject’s individual characteristics, circumstances, and postmortem macropathologic changes. In this retrospective study, based on 1590 consecutive cases of bodies found in water and undergoing autopsy at the Department of Forensic Medicine, University of Helsinki, from 1976 to 1998, the frequency of circumstantial data and macropathologic changes crucial for the diagnosis of drowning were determined. The fatal events were eyewitnessed in 403 cases (25.3%), and suicide notes were found in 83 cases (5.2%). External foam, frothy fluid in airways, and overlap of the anterior margins of lungs were found in 275 (17.3%), 739 (46.5%), and 669 (42.1%) of the cases, respectively, but no one of these changes, tested against dry-land controls, were specific for drowning. The association of external foam and overlap of the lung margins was exclusive of drowning but was observed in only 176 cases (11.1%). After cross-analysis, 964 (60.6%) of the cases had no circumstantial data or macromorphologic pathologic findings that allowed a definite diagnosis of drowning. The diagnostic problems in putative drowning cases, based on this study sample, have not been overrated. Studies to investigate and improve the reliability of complementary methods for the diagnosis of drowning are warranted.