Diabetes mellitus has reached epidemic proportions in both the United States and worldwide with most authorities reporting a doubling in the prevalence of diabetes over the last 20-30 years. While this epidemic is closely tied to obesity, diabetes mellitus presents potential clinical challenges over and above that observed with obesity alone. From a women's health care prospective, this rise in diabetes may impact a woman's health across her lifespan. More specifically, diabetes impacts not only pregnancy as well as well as other medical conditions, but increases the risk for the development of various malignancies. From a gynecologic cancer standpoint, diabetes is most closely associated with endometrial adenocarcinomas, although increasing attention is being placed upon diabetes and ovarian cancer. Attention is also being placed on the potential role of metformin and its impact on outcomes in diabetics with cancer, as well as a potential preventative and/or adjunctive therapy for gynecologic cancer.