Abstract: In this study, the histological changes observed in Mus musculus’ stomach mucosa which was exposed to hunger and thirst were examined. Pieces from chest and stomach cavities were taken in the 1st, 2nd, 3rd, 4th and 5th days following last feeding. These tissue specimens were fixed by using 10% neutral formalin which was compressed. After routine tissue checks, the tissue pieces were sunk into paraffin and some blocs were prepared. With the aim to examine histological structures of the pieces taken, they were colored with Hematoxylin and Eosin (H and E). An increase in the number of blood cells taken part in stomach tissue was observed in the first twenty four hours. A widening in glandular epithelium lumen was seen after two days. A tendency to slim was observed in mucosa layer of the surface and glandular lumen during hunger. In the stomach mucosa, structural changes were caused by hunger and thirst. It was found that these changes were in direct proportion with hunger and thirst duration.