Increases in the generation of organic wastes, in addition to decreases in natural resources, make it necessary to recycle these waste materials. In soils, the application of wastes as organic fertilizers, allows to reincorporate nutrients to the biogeochemical cycles. The application of wastes in agriculture has carried out with it problems associated with phosphorus (P) overapplication in soils and contamination of water bodies. Phosphorus inside the waste matrix forms organic and inorganic compounds which have different bioavailabilities. The more important factors that influence the bioavailability of P in soils, organic wastes and soil-organic waste amendments are: the soil solution pH, adsorption reactions, organic matter, phosphatase activity and low molecular weight of organic acids. In the wide range of organic wastes, purines and compost have been selected to illustrate the effects of the factors previously mentioned on the bioavailability of P in soils. According to the analyzed information, we can suggest that it would be necessary to implement technologies to increase the bioavailability of P in the waste matrix to produce an efficient organic fertilizer with high P bioavailibility when it is applied in soils. According to the analyzed information, we can suggest that it would be necessary in the prospect future, the possibility to studynew technologies for increase the bioavailability of P in the waste matrix to produce an efficient organic fertilizer with high P bioavailibility when it is applied in soils.