Soil and sediment pollution as a result of historical use of persistent organic pollutants (POPs) is common in Australia. Understanding of their fate and behaviour in soil is crucial for a proper assessment of their potential risk and impact on environment. Organic contaminants in soils undergo a range of processes, namely sorption, desorption, sequestration and ageing; all of which help immobilize the compounds in soils rendering them progressively less bioavailable with time. While these phenomena have been known for decades now, the bioavailability of organic contaminants is relatively rarely taken into account during risk assessment. Substantial new knowledge in literature provides new opportunities to do so. Recent research on interactions of organic contaminants with certain fractions of organic carbon in soils has shed new light on the inadequacy of simple partitioning as a mechanism of contaminant sorption as well as helps explain why contaminants have low bioavailability in soils and sediments, enriched with certain type of organic carbon. This research highlights the need for better assessment of bioavailability of contaminants such as POPs. Recent developments on tools to assess bioavailability have demonstrated that physico-chemical techniques can provide a uniform and standard surrogate for measurement of bioavailability of organic contaminants in soil and sediments. This paper will focus on how the new knowledge in the area of organic contaminant interactions with soil and its constituents, and on the biomimetic tools for assessment of bioavailability of organic contaminants, can and should be harnessed to obtain more realistic risk assessment and cost-effective remediation of organic contaminants in soils.