Organic acids, such as malate, citrate, and oxalate, play a critical role in rhizosphere processes, including nutrient acquisition, metal detoxification, alleviation of anaerobic stress, mineral weathering, and pathogen attraction. However, their exact role in these processes remains unclear due to limited understanding of the mechanisms of plant organic acid release and their fate in soil. This review summarizes current knowledge on organic acid levels in plants, plant efflux, soil reactions, and microbial considerations. It highlights that organic acids are released from roots in response to various environmental stresses, such as Al, P, and Fe stress, and anoxia. These responses are highly stress- and plant-specific. The sorption of organic acids to the mineral phase and their mineralization by soil microbial biomass are critical in determining their effectiveness in rhizosphere processes. Organic acids are low-molecular weight compounds found in all organisms, characterized by the presence of one or more carboxyl groups. They can carry varying negative charges, allowing complexation of metal cations and displacement of anions from the soil matrix. They are involved in various soil processes, including nutrient mobilization and uptake, metal detoxification, microbial proliferation, and mineral dissolution. However, there is limited direct evidence supporting these hypotheses. The review provides a schematic diagram of major organic acid fluxes and pools in soil, which will form the basis of this review. Without knowledge of the size and rates of flux between these pools, it has been impossible to determine the importance of organic acids in a complex soil environment. Organic acids are present in plant roots in varying concentrations, with lactate, acetate, oxalate, succinate, fumarate, malate, citrate, isocitrate, and aconitate being the primary anion components. The organic acid content of plants is influenced by their type of C fixation, nutritional status, and age. The total concentration of organic acids in roots is typically around 10–20 mM, which can be compared with other main organic solutes present in root cells, such as amino acids and sugars. The spatial distribution of these solutes in maize roots is shown in Figure 2, illustrating the spatial heterogeneity of solutes within a single root. The degree of cation-anion imbalance in roots is a primary factor determining organic acid levels. Roots grown on NH4+ have lower organic acid concentrations than those grown on NO3−. The vacuole can occupy a significant proportion of root cells, and the concentration gradient between the cytosol and soil solution determines the rate of efflux. The concentration of organic acids in the cytosol must be closely controlled to meet the kinetic and inhibitory requirements of enzymes involved in cellular metabolism. When an accumulation of organic acids is observed in roots, it may simply reflect an increase in vacuolar concentration or volume.Organic acids, such as malate, citrate, and oxalate, play a critical role in rhizosphere processes, including nutrient acquisition, metal detoxification, alleviation of anaerobic stress, mineral weathering, and pathogen attraction. However, their exact role in these processes remains unclear due to limited understanding of the mechanisms of plant organic acid release and their fate in soil. This review summarizes current knowledge on organic acid levels in plants, plant efflux, soil reactions, and microbial considerations. It highlights that organic acids are released from roots in response to various environmental stresses, such as Al, P, and Fe stress, and anoxia. These responses are highly stress- and plant-specific. The sorption of organic acids to the mineral phase and their mineralization by soil microbial biomass are critical in determining their effectiveness in rhizosphere processes. Organic acids are low-molecular weight compounds found in all organisms, characterized by the presence of one or more carboxyl groups. They can carry varying negative charges, allowing complexation of metal cations and displacement of anions from the soil matrix. They are involved in various soil processes, including nutrient mobilization and uptake, metal detoxification, microbial proliferation, and mineral dissolution. However, there is limited direct evidence supporting these hypotheses. The review provides a schematic diagram of major organic acid fluxes and pools in soil, which will form the basis of this review. Without knowledge of the size and rates of flux between these pools, it has been impossible to determine the importance of organic acids in a complex soil environment. Organic acids are present in plant roots in varying concentrations, with lactate, acetate, oxalate, succinate, fumarate, malate, citrate, isocitrate, and aconitate being the primary anion components. The organic acid content of plants is influenced by their type of C fixation, nutritional status, and age. The total concentration of organic acids in roots is typically around 10–20 mM, which can be compared with other main organic solutes present in root cells, such as amino acids and sugars. The spatial distribution of these solutes in maize roots is shown in Figure 2, illustrating the spatial heterogeneity of solutes within a single root. The degree of cation-anion imbalance in roots is a primary factor determining organic acid levels. Roots grown on NH4+ have lower organic acid concentrations than those grown on NO3−. The vacuole can occupy a significant proportion of root cells, and the concentration gradient between the cytosol and soil solution determines the rate of efflux. The concentration of organic acids in the cytosol must be closely controlled to meet the kinetic and inhibitory requirements of enzymes involved in cellular metabolism. When an accumulation of organic acids is observed in roots, it may simply reflect an increase in vacuolar concentration or volume.