Concentrations of reducible trace metals (available to hydroxylamine hydrochloride-acetic acid; HA) have been determined in sediments from contrasting estuaries around the United Kingdom; specifically, estuaries receiving contemporary anthropogenic inputs from catchments which are urbanized and industrialized to varying degrees (Clyde, Dee, Forth, Loughor, Mersey and Poole Harbour), and estuaries receiving inputs from mineralized catchments where working of sulphidic ore deposits was important in the past (Fal, Hayle, Helford and Tavy). Mean estuarine ratios of Fe:Mn ranged from less than 10 (Dee, Mersey, Loughor) to about 100 (Fal, Poole Harbour); inter-estuarine variations in the mass contributions of Fe and Mn were attributed to differences in geological and hydrological catchment characteristics, while intra-estuarine variations were attributed to local differences in hydraulic sorting of sediment and redox conditions. The relative contributions of hydrous Fe and Mn oxides to the accumulation of trace metals (Cr, Cu, Pb, Zn) was evaluated by applying different regression analyses to each estuarine dataset. Overall, the most significant correlations were with Fe, and in estuaries draining mineralized catchments where well-defined contaminant metal sources exist; poor correlations in other cases were related to the dissolution of additional metal-bearing phases, including carbonates, by the digest (Dee, Loughor), or the inability of low energy environments (Clyde, Poole Harbour) to buffer the impacts of local sources of contaminant metals.Mean estuarine concentrations of Pb and Zn ranged from about 25μgg −1 (Poole Harbour) to 200μgg −1 (Hayle), and 80μgg −1 (Forth) to 1500μgg −1 (Hayle), respectively. Pooled Pb and Zn data were defined by a single regression equation which was not controlled by the availability or abundance of oxidic material, suggesting common environmental and anthropogenic sources and similar sorptive and post-depositional behaviours for these metals. Pooled Cr and Cu data, however, exhibited distinct groupings which were attributed to the differential sources and sorptive behaviours of these metals. Naturally occurring Cr is highly resistant to the HA digest and excess concentrations above a baseline of about 2·5μgg −1 , which characterises sediment from mineralized catchments, are the result of contamination from contemporary or historical industrial processes (e.g. mean concentrations in the Clyde and Forth are about 30μgg −1 ). Copper is available to the HA digest in sediments of estuaries draining mineralized catchments, where concentrations, locally, exceed 750μgg −1 , but is highly resistant to the HA digest in sediments of industrialized estuaries, where concentrations are, typically, between 5 and 40μgg −1 . This is because Cu derived from the dissolution of sulphidic minerals adsorbs readily to hydrous Fe oxides, while Cu derived from contemporary industrial and municipal sources appears to interact with anthropogenic organic matter and the resulting complexes partition into sediment organic matter which is relatively resistant to the HA digest.Although the HA digest cannot readily resolve geochemical and anthropogenic metals in hydrous oxides (and other sorbents dissolved by HA), the availability of metals like Cr and Cu may give some indication of the history of the contaminant (e.g. its source and subsequent particle–water interaction mechanism). More generally, from a management and assessment standpoint, this approach affords a first-order estimate of contaminant metal loading which is geochemically and biologically available.