Lactic acid (LA) is an organic compound used in several industries, such as food, textile, chemical, and pharmaceutical. The global interest in this product is due to its use for the synthesis of numerous chemical compounds, including polylactic acid, a biode-gradable thermoplastic and substitute for petroleum-derived plastics. An in-depth overview of the use of industrial and household wastes as inexpensive substrates in order to reduce the cost of LA production is presented. A review is carried out of the biotech-nological aspects that must be taken into account when using some wastes with high transformation potential to produce LA in a submerged culture, as well recommendations for their use. The advantages and disadvantages of different types of treatments used for the transformation of waste into suitable substrates are considered. Several methods of fermentation, as well as genetic strategies for increasing the production, are summarized and compared. It is expected that in a few years there will be many ad-vances in these areas that will allow greater large-scale production of LA using agroindustrial or household wastes, with potential positive economic and environmental impact in some regions of the planet.