Background/Aim. Drug abuse remains a significant social problem in many countries. The aim of the study was to estimate association between pulmonary histopathological changes and results of toxicological analyses in forensic autopsies of illicit drug users. Methods. This investigation was performed in the Institute of Forensic Medicine, Belgrade, and in the Clinical Center, Department of Forensic Medicine, Kragujevac, from 2000 to 2004, and included 63 medicolegal autopsies of heroin or other drug consumers who suddenly died. Autopsies, postmortem toxicological examination of drugs and serological analyses of anti- HIV/HBV/HCV antibodies were performed. Results. The deceased persons were mostly male, 46/63 (73.01%), ranged in age from 19 to 49 years (mean 31 years) and all were whites. Postmortem toxicological examination was performed on all of the deceased persons and drugs in the fatal range were identified in only eight of them (12.7%), in the toxic range in ten (15.87%), and in minimal concentrations in 35 (55.56%) of the deceased persons. Drugs identified in the fatal, toxic or minimal range included heroin-morphine (38/53), cocaine (4/53), tramadol (3/53), and lorazepam (1/53). In the 7 remaining subjects, ethanol in combination with heroin was found in 4 cases, and diazepam in combination with heroin in 3 cases. Dominant pathomorphological changes were findings in the lung tissue. Most common histological changes observed in drug users were pulmonary edema - 55/63 (87.3%), acute alveolar hemorrhages - 49/63 (77.78%), hemosiderin-laden macrophages (siderophages) - 52/63 (82,54%), and emphysematous changes - 51/63 (80,95%). Conclusion. Pulmonary edema is the frequent non-specific autopsy finding which is associated with virtually all routes of drug administration. The histopatological study is necessary to determinate a cause of death when a deceased person has the history of dependence or abouse of psychoactive drugs with negative toxicological results.