To investigate oleic acid biodegradation, 47 fungal strains were tested with modified Czapek Dox broth media containing oleic acid, and their biodegradative activities were assayed by measuring the release of $[^14C]CO_2$ from the $^14C-$labeled oleic acid. After 72 h of cultivation, Aspergillus flavus, Aspergillus ochraceus, and Alternaria species metabolized approximately $25\%;to;35\%$ of the supplied oleic acid. The relationship between the fungal degradation of oleic acid and the fungal growth was also examined using 7 strains of Aspergillus niger. A. niger. YMC 0100 and YMC 0322 degraded about $26\%$ of the oleic acid after 72 h, while their germination ratios were more than $30\%$.