Several composting and wastewater treatment facilities in the Austrian state of Styria produce materials that often exceed regulatory limits for one or more trace metals and must develop strategies to reduce these concentrations. This research was conducted to determine if metals loads in composts and biosolids are influenced by background levels in the regional geology. Georeferenced geochemical databases for stream sediments and soils in Styria were analyzed using a geographical information system (GIS) to establish background concentrations of Cd, Cr, Cu, Hg, Ni, Pb, and Zn for most geological units in the state. A second database was developed that included all composting and wastewater treatment facilities in Styria and contained metals concentrations data for composts and biosolids over a 10 year period. Assigning the production facilities to the appropriate geological units allowed us to determine the extent to which background geology influenced metals loadings in composts and biosolids. For most metals studied and in most areas of Styria there was no evidence that regional geology was influencing metals loads in biosolids and composts. There was a strong probability, however, that composts and biosolids produced in areas with high background Ni and Cr would contain elevated Ni and Cr. In such regions any attempts to reduce Ni and Cr in compost and biosolids must identify and then minimize the primary pathways by which these metals are transported to composts and biosolids. This research was funded by the Styrian Government Division of Sustainable Waste Management.