Onychomycosis caused by the genus aspergillus is extremely rare in Korea and only one case due to A. sydowi has been reported. We experienced two casea of onychomycosis infected with A. repens, which were healthy adults. The first case was a 29 year-old male who developed thickening and dark discoloratian of 1st, and, 3rd and 5th toe-nails of left foot from about 5 months on. The second case was a 27 year-old male who developed thickening and yellow-whitish discoloration of the nail of right thumb from about 3 rnonths on. In both cases, direct examination of the affected nails showed many thick bluish hyphae and spore chains, and A. repens was isolated. Our cases were first reported through the Korean literature.