Tomato is a vegetable culture that traces its origins back to South America. Today, its cultivation is widespread all over the world, and more than 7000 types of this culture have been developed. In each method of cultivation there are certain risks of the appearance of certain pathological conditions or for shortened diseases. The basic division into plant diseases is based on the causes, and so there are abiotic (physiological) and biotic diseases.Abiotic diseases are due to poor environmental conditions, for example, an excess or lack of certain feed, light, heat, water and moisture. How much the plant will suffer from a physiological disease depends on the volume of a certain deficiency/excess and the duration of such a condition. Certain physiological diseases can be caused by a live pathogen, in such a way as to block the adoption of some feed. Biotic diseases are always caused by a living organism, and the groups of organisms that will be described in this paper are viruses (not organisms in the true sense), bacteria and fungi. The basic protection against the development of the disease is prevention, which includes proper tillage, meliorrative procedures, the selection of a resistant varietes or hybrids, crop rotation and hygiene of tools and breeding premises. If the appearance of a particular pathogen is predicted, preventive application of pesticides is required. In addition to the direct destruction of pathogens, it is necessary to destroy vectors that are carriers of them.