Lung autopsy specimens were obtained on consecutive coroner's cases of Hispanic males in Fresno County, California (n=86) to determine the prevalence of lung disease. Specimens were fixed by standardized protocol. Airway pathology and dust content were scored. Histological changes in lung tissue samples of farmworkers were compared to non-farmworkers. Of the first 86 cases, farmworkers comprised 51% (51% smokers) and non-farmworkers 49% (49% smokers). Microscopic exam to the sixth airway generation demonstrated little mineral dust accumulation, but respiratory bronchioles showed evidence of wall thickening and remodeling associated with heavy carbonaceous and mineral dust accumulation. Increased collagen and interstitial cells including dust-laden macrophages were also present with the wall changes. These changes were associated with agricultural work history, and were independent of cigarette smoking. Independently-rated mineral dust small airways disease, pneumoconiosis, and lymph node fibrosis predominated in the farmworkers compared to the non-farmworkers; 71 % vs. 29%, 19% vs. 5%, and 69% vs. 31 %, respectively. There was also an association between increasing age and dust concentration present in the lungs. Hispanic males in Central California show early, subclinical histopathological changes consistent with silicosis and mixed-dust pneumoconiosis. Agricultural dust exposure is associated with mineral dust airways disease independent of age and cigarette smoking. The natural history and clinical significance of these changes remains to be determined.