Diabetes mellitus (DM) is one of the most common diseases all over the world. The effect of this endocrine disease on body systems cannot be ignored, where its oral side effects are well distinguished. As this disease incident is increasing dramatically, it is essential for the health care providers to be fully aware of the disease diagnosis, management and to deal with it in a full confident. This review discusses the disease itself, its complications, methods of diagnosis as well as its management. Furthermore, oral manifestations and dental considerations that should be followed when treating patients with diabetes mellitus have been discussed in this review.