Background: Forensic pathologists find it difficult to ascertain the actual reason for death and the actual mode of death in drowning cases. It is commonly acknowledged that not all people whose dead bodies are found in water perished from drowning. The medico-legal inquiry includes an important component that examines dead bodies collected from the water. The corpse's time in the water continues to be the main concern. This aids in determining the time of death, which is crucial to any medico-legal investigation. The traditional histological analysis of hematoxylin and eosin (H&E)-stained oral soft tissue can be crucial in the assessment of this feature. Hence, this study was done to compare histological changes in the tissue specimens kept in tap water, river water, and seawater for different intervals of time.Materials and methods: One hundred eighty specimens were obtained from 180 dead bodies and divided randomly into three categories. Category A consisted of 60 specimens submerged in tap water, Category B of 60 specimens submersed in river water, and Category C consisted of 60 specimens submerged in seawater. The specimens underwent routine histological processing and H&E staining. The microscopic evaluation of specimens was carried out at two hours and on the first, second, third, fourth, and fifth days of submersion. Details were recorded regarding the structural changes, cellular changes, connective tissue changes, changes in the basement membrane, and intensity of H&E staining. Once the process of routine histological processing and H&E staining was completed for each study specimen, an evaluation of microscopic changes in the tissue was made.Results: The present study revealed that seawater preserved tissue best and for a longer period than river water and tap water. River water preserved tissue better than tap water. In pathologic tissue, details were preserved for much longer. It was noted that in squamous cell carcinoma, connective tissue was destroyed earlier than epithelium, in contrast to normal tissue where epithelium was destroyed before connective tissue.Conclusion: This study indicates that the medium of submersion in drowning victims affects the histopathological features. The time of death is an important aspect of forensic investigation. Considering this, all cases of drowning should be very carefully evaluated, and the medium taken into consideration while determining the time of death, as tissue degrades faster in freshwater than in seawater.