Aim: Silicosis has long been recognized as an important occupational lung disease that is included in the group of pneumoconiosis. As already well-known silicosis is a progressive pneumoconiosis characterized by fibrosis in the lungs. Also, chronic exposure to silica may cause chronic obstructive pulmonary disease, emphysema, lung cancer, and pulmonary fibrosis. Asymmetric dimethyl arginine (ADMA), symmetric dimethyl arginine (SDMA), and L-NMMA (NG-mono-methylated-L-arginine) are the products of protein arginine methyltransferase (PRMT) enzymes. The aim of this study is to investigate the relationship between silicosis and arginine metabolites in silica exposed and non-exposed workers. Material and Method: 180 male subjects (90 non-exposed workers (age matched-control) and 90 workers diagnosed with silicosis occupational physician based on radiological and clinical findings and exposure history-(silica-exposed) were included in this study. The serum levels arginine, ADMA, SDMA, and L-NMMA were determined using enzyme-linked immunosorbent assay. Results: ADMA, SDMA, L-NMMA values were significantly higher in the silica-exposed group compared to the control group. The positive correlations were observed between methylated arginine parameters such as ADMA and SDMA, ADMA and L-NMMA levels (r=0.43, r=0.60; p<0.01). The negative correlations were found between SDMA and arginine/ADMA, L-NMMA, and arginine/ADMA, arginine and SDMA/ADMA, arginine/ADMA and SDMA/ADMA levels, respectively (r=-0.22; r=-0.22, r=-0.34, r=- 0.29; p<0.01). The strongest positive correlation was found between arginine and arginine/ ADMA ratio, and the strongest negative relationship between ADMA and arginine/ADMA ratio, respectively (r=0.87; r=-0.48; p<0.01). Conclusion: The results could provide additional insight into understanding the disease and the potential for developing biomarkers.