BACKGROUND: Small manufacturing businesses often lack important safety programs. Many reasons have been set forth on why this has remained a persistent problem. METHODS: The National Machine Guarding Program (NMGP) was a nationwide intervention conducted in partnership with two workers' compensation insurers. Insurance safety consultants collected baseline data in 221 businesses using a 33-question safety management audit. Audits were completed during an interview with the business owner or manager. RESULTS: Most measures of safety management improved with an increasing number of employees. This trend was particularly strong for lockout/tagout. However, size was only significant for businesses without a safety committee. Establishments with a safety committee scored higher (55% vs. 36%) on the safety management audit compared with those lacking a committee (P < 0.0001). CONCLUSIONS: Critical safety management programs were frequently absent. A safety committee appears to be a more important factor than business size in accounting for differences in outcome measures.