Diabetes mellitus (DM) is a metabolic disorder which is the most alarming disease of the modern era, which occurs as a result of lack of insulin secretion or reduced insulin secretion or peripheral insulin resistance. Owing to the lifestyle changes, food habitus and stress, it has now become a pandemic. The incidence of diabetes is rapidly increasing worldwide at a dangerous rate. Over the past 30 years, the status of diabetes has changed from being considered as a mild disorder of the elderly to one of the major causes of morbidity and mortality, affecting the youth and middleaged people. As per the WHO, 171 million cases were reported in 2000 and are expected to increase to 366 million by 2030. DM incidences continuous to rise and pose a serious threat to human health. DM prevalence is increasing due to lifestyle, ethnicity, and age. Insulin has remained the main treatment for Type 1 diabetes and many Type 2 diabetic patients since its discovery, through parenteral insulin administration. Nanoparticles (NPs), which are minute structures ranging from size 1 to 100nm, are being studied for the treatment of various diseases. Considering the versatility of NPs, it also gives hope for better treatment options in diabetes. Different strategies have been used to manipulate insulin by using NPs, such as encapsulated delivery, etc. The objective of this chapter is to resolve the issues concerned with the oral delivery of insulin and also to discuss possible routes for the administration and the use of NPs for the best delivery of insulin. Nanotechnology, as a promising field, has opened new ways for the treatment of DM.