Persons working in mines, plating factories, cement industries and so on are mainly exposed to chromic substances. Among them, nasal septal perforation(NSP) is caused by inhalation of chromic acid, a highly corrosive and toxic material. To our knowledge, there has been no report of the detailed findings of the olfactory function in subjects exposed to chromic acid. So we present the results of olfactory function test measured by T & T dolfactometer and compare the olfactory function test with duration of chromium exposure, chromium concenturation of blood, AST/ALT in blood and protein in urine. We performed this study in 11 patients with NSP and 31 subjects without NSP. The obtained results were as follows : 1) the age distribution of the subjects involved in this study was from 23 to 57 years old (average 37.7 ± 8.4 years old) and the duration exposed to chromium was from 2 months to 25 years(average 8.6 ± 6.9 years). 2) The olfactory function was checked by detection and recognition thresholds in five odorants. The detection and recognition thresholds of laborers dealing with chromium were more increased than normal control group. 3) There was no correlation between the duration and the olfactory threshold levels. 4) Only, detection thresholds of odorant B and recognition thresholds of C were increased in the relation with concenturation of chromium in urine(p=0.0006, p=0.0317) and there were no relation in others. 5) The olfactory thresholds in the group of nasal septal perforation was higer than the group of intact septum in all odorants, but only detection threshold of odorant B, C, D and E were statistically significant.