This report summarizes the results of an analysis conducted by the University of Tennessee's (UT) Center for Clean Products and Clean Technologies for the U.S. Environmental Protection Agency's Design for the Environment (DfE) Lead-Free Solder Partnership (LFSP). The DfE LFSP is a voluntary, cooperative partnership among the DfE Program, UT, the IPC- Association Connecting Electronics Industries (IPC), the Electronic Industries Alliance (EIA), several individual electronics companies, and other interested parties. The partnership assessed the environmental life-cycle impacts of selected lead-free solders as alternatives to tin-lead solder. The DfE LFSP analysis also provides an assessment of the recyclability and leachability of the solders. The purpose of the lead-free solder study is threefold: (1) to evaluate the life-cycle environmental impacts of selected lead-based and lead-free solder alternatives using life-cycle assessment (LCA); (2) to evaluate the effects of lead-free solders on leachability, recycling, and reclamation at the end-of-life; (3) to identify data gaps or other potential areas of analysis for future investigation by EPA or industry. This study used LCA to evaluate both lead-based and lead-free solder alternatives. LCAs, which are generally global and non-site specific in scope, look at the full life cycle of the product being evaluated, from materials acquisition to manufacturing, use, and end-of-life (i.e., final disposition). The LFSP LCA considers impacts related to material consumption, energy use, air resources, water resources, landfills, human toxicity, and ecological toxicity, as well as leachability and recycling.