One of the economy key sectors of Republic of Moldova and Romania is the wine sector, where a progressive trend has prevailed in recent years. But to increase its efficiency it is necessary to use the raw material in a complex way, producing both famous wines and other necessary products, as well as to comply with the rigors of ecological standards. The issue of wine by-products draws the attention and interest of researchers, regulators, industry and consumers and has urged the European Community to a zero waste economy by 2025. The article deals with the chemical composition of the main parts of grapes which depend on a number of factors, such as variety, climatic conditions of the year, vine and wine making practices, condition of the grapes, their maturity, etc. There have been presented physico-chemical characteristics of the wastes obtained from the grapes processing such as: bunches, grape pomaces, piquette and diffusion juice, seeds, wine yeast, tirighia and vinasse. Thus, by making use of wine wastes, a number of valuable products can be obtained that can be used for different purposes.