BACKGROUND: Metal working has been identified as an industry with one of the highest rates of non-fatal injury in the United States. However, the systematic evaluation of machine-related hazards is lacking. METHODS: The Minnesota Machine Guarding Study evaluates the effectiveness of a peer-based technical and educational intervention designed to reduce exposure to amputation hazards among workers in small machining/metal working businesses. The data presented here provide a profile of machine guarding in small (5-100 employees) metal fabrication businesses in Minnesota. A set of checklists to quantify machine-guarding practices were developed. Up to 25 randomly selected machines were evaluated in each facility. In addition, walk-through surveys were conducted to assess machine-related safety practices and programs (e.g., lock out-tag out). RESULTS: A total of 824 machines were evaluated. Overall, 55% (SD 11%) of items addressing machine guarding were present. No single machine complied with all critical safety requirements. Shops with safety committees tended to have better scores than did shops without safety committees. Thirty-five percent of all businesses had established machine guarding procedures and 17% provided training in machine guarding (e.g., use of machine guards and devices in daily operations) to their employees. CONCLUSIONS: These data indicate that machine guarding and related safety programs in small metal fabrication businesses were inadequate. The data also suggest that safety committees are an important component in improving machine safety and related programs in small businesses.