Aims- To assess the correlation of pulmonary functional status including 6MWT in silicosis patients according to ILO guidelinesMethods-A descriptive study conducted at Dr S N medical college Jodhpur, India from july 2013 to august 2014. Total of 109 patients were selected on the basis of history of exposure to silica in mines, chest x-ray was used to confirm the diagnosis of silicosis and to classify them according to ILO guidelines.Spirometry & 6MWT was performed by each patient. Pearson chi-square test & welch ANOVA was used for statistical analysis.Results-FEV1/FVC ratio, FEV1, FVC of patients with grade 1/0 & 1/1 was 97.15±7.1, 91.15±8.9%, 93.3±6.4% respectively, all parameters were within normal limits & gradually decreased with increasing ILO grading & decreased to 62.5±22.6, 36.25±14.2% & 60±18.42% respectively in grade C of PMF patients, all these change in parameters were highly significant(p<0.001).The 6MWD,Spo2 desaturation & BORG dyspnea scale during 6MWT in patients with grade 1/0 &1/1 was 439±36.7m, 1.03±0.82% & 0.54±0.66 respectively and changed gradually with advancing ILO grading of silicosis to 251.25±12.84m, 9.75±1.5% & 5.5±1 respectively in grade C of ILO with a difference in 6MWD of 188m, Spo2 desaturation of 8.72% & BORG dyspnea scale of 4.96, these changes were statistically significant (p<0.001).Spirometry & 6MWT parameters mainly FVC,6MWD & Spo2 desaturation were significantly changed in patients with PMF compared to simple silicosis according to ILO.Conclusion-Along with chest x-ray, spirometry & 6MWT, both are simple & non-invasive but highly useful in assessing the severity of silicosis & functional capacity in silicosis patients.