The principle objective of this review article is to present to plant nutrition specialists some interesting aspects of the role of organic acids in improving the availability of nutrient elements in calcareous soils in order to promote more research in this area. The rhizosphere is the zone of soil immediately surrounding plant roots that is modified by root activity. In this critical zone, plants respond to their environment. As a consequence of normal growth and development, a large range of organic and inorganic substances are exchanged between the root and soil, which inevitably leads to changes in the biochemical and physical properties of the rhizosphere. Plants also modify their rhizosphere in response to certain environmental signals and stresses. Organic anions are commonly detected in this region, and their exudation form plant roots have now been associated with nutrient deficiencies and inorganic ion stresses. Organic acids such as citrate, oxalate and malate are active in many of the roots natural processes including nutrient absorption, reducing metal toxicity, mineral weathering and pathogens attraction. A full assessment of their role in these processes, however, cannot be determined unless the exact mechanisms of plant organic acid release and fate of these compounds in the soil are more fully understood. This review therefore, includes information on organic acid levels in plants, soil reactions (soil solution concentration, sorption) and microbial considerations (mineralization). In summary, the release of organic acids from roots can operate by multiple mechanisms in response to a number of well-defined environmental stresses (e.g., P and Fe stress). These responses, however, are high stress and plant-species specific. In addition, this review indicates that the sorption of organic acids to the mineral phase and mineralization by the soils microbial biomass are critical to determining the effectiveness of organic acids in most rhizophere processes.