Here we critically review analytical procedures for the extraction of soil organic phosphorus. We do not address the origins, behaviour, or biological utilisation of soil organic phosphorus, which have been reviewed extensively [5], [6], [7], [8], [9], [10] and [11]. Nor do we consider the literature on aquatic sediments, which are sufficiently different from soils to warrant separate consideration. Our aim is to identify key problems with current methodology that must be addressed to advance research on this important component of soil biogeochemical cycles.