A sediment-based toxicity test was designed to investigate the biological response of the amphipod Corophium volutator exposed to three common arsenic minerals, namely realgar (AsS), orpiment (As2S3) and arsenopyrite (Fe[AsS]). The LD50 for the loaded minerals and the added As in the sediment showed mineral-dependent toxicities increasing in the order of AsS approximate to As2S3 < Fe[AsS] (224-1329 mg As kg(-1)). The exposed animals accumulated arsenic in a mineral-dependent manner similar to the observed toxicity, with AsS approximate to As2S3 and both higher than that for Fe[AsS]. The arsenic concentration in C. volutator at the LD50 exposure exhibits the same mineral independences, confirming that the response is arsenic specific. A significant increase in extractable inorganic arsenic in the tissue (over 100-fold) at higher arsenic exposures (up to 3% mineral-loading, w/w) was revealed hence no significant biotransformation of inorganic arsenic. C. volutator is sensitive to arsenic and has the potential to be used as a bio-indicator to assess the toxicity of arsenic-containing sediments or arsenic-containing mining wastes.