Rice (Oryza sativa) represents the major food, feeding more than half of the world population every day. The dependence of such a large population to meet their daily dietary requirements on this tropical crop causes large-scale production in different parts of the world. Since the crop thrives comfortably in humid climates, the areas differing in such environmental conditions require the application of agrochemicals and require an extensive crop management programme to efficiently manage the diseases that hamper the crop's growth. The rice diseases, mainly caused by bacteria, fungi, and viruses, lead to significant damage and loss in the crop yield. The fungal diseases mainly attack stems, roots, grains, and foliage. The level of plant damage caused by these diseases depends on the innate capacity of the crop species to withstand the disease, severe environmental conditions, soil fertility and composition, the effect of agrochemicals, and the stage of plant growth. This chapter provides a concise discussion of the various diseases caused by bacteria, fungi, and viruses that impede rice crop growth.