Cases: Three men with silicosis and mediastinal lymphadenopathy presented with proteinuria and worsening serum creatinine. Renal biopsies were performed. Their background and biopsy findings are summarized in Table 1. Discussion: Silicosis, asthma and COPD are major occupational respiratory diseases in workers with silica exposure (Park SY, et al. J Korean Med Sci. 2014.). RA associated with silicosis (Caplan’s syndrome) is believed to be caused by inflammasome activation by crystalline silica phagocytosed by macrophages (Leung CC, et al. Lancet. 2012.). Past literature (Osorio AM, et al. AJKD. 1987.) and our findings suggest that various patterns of immune complex deposition in the glomeruli may cause membranous nephropathy or membranoproliferative glomerulonephritis in silicosis patients even decades after silica exposure. Silicosis, mediastinal lymphadenopathy and proliferative glomerulonephritis may compose a syndrome. These findings may help investigate the etiology of increased membranous nephropathy in smokers (Yamaguchi M, et al. PLOS ONE. 2014.) or in residents in air-polluted areas (Xu X, et al. JASN. 2016.). Table 1. Summary of the cases