Cell fusion is a cellular mechanism in which cell membranes of two or more cells fuse to become a new hybrid cell. Cell fusion plays an important role in several physiological tasks such as fertilization, organogenesis, inflammatory response, and tissue repair. However, cell fusion aids in the development of a wide range of pathological conditions such as inflammation and cancer. Cell fusion of normal somatic cells is a tightly controlled process that is limited to only a few cell types in humans, resulting in terminally differentiated multinucleated cells incapable of proliferation. However, this tightly controlled process becomes dysregulated due to genetic alterations and leads to the development of cancer. In this review, the implications of cell fusion and its role in carcinogenesis are discussed in detail.