Hamsters are one of the commonly used animal species in research related to virology and infectious agents. Hamsters are similar to human beings in many metabolic and physiological processes. Though the use of hamsters in research has declined in the last few decades, the genetically engineered Syrian hamster (GESH) model is seeing increased popularity due to advancements in gene-editing technologies like CRISPR/Cas9. The presence of immunologically privileged large highly distensible non-glandular cheek pouches makes hamsters a preferred model for oral carcinogenesis, microvascular investigations of inflammation, ischemia-reperfusion investigations, tumor development, and vascular smooth muscle function. Due to the unique immune system of hamsters, skin allografts are not rejected to the degree as compared to other models and have a higher susceptibility to certain infections. It is already known that for, cell culture experiments, Chinese hamster ovary (CHO) cells are extensively used. This chapter will briefly discuss general anatomy, physiology, husbandry, and reproduction, followed by references to reported research uses.