Certified Safe Farm (CSF) is a multifaceted intervention including clinical Occupational and wellness screening, education, and on-farm safety audits with set safety standards, and performance incentives. Five years of respiratory health outcomes are reported in 150 CSF intervention farmers and 158 matched controls. Standardized health interviews and occupational histories were analyzed with descriptive statistics to determine prevalence rates. There was a 100% response rate from the standardized telephone interviews, and respectively a 94% and 89 % response rate from the self-administered occupational health history questionnaire for the CSF intervention and the comparison population. The overall rate for occupational respiratory conditions was 17/100 person-years. At baseline there was no difference between the prevalence of respiratory symptoms between the CSF and control groups. However, over the course of the intervention, the CSF farmers increased their use of personal protective respiratory equipment at work, and experienced fewer episodes of acute symptoms of organic dust toxic syndrome (ODTS). The Certified Safe Farm intervention appeared to affect increased use of respiratory protection and decreased symptoms of ODTS.