The fatty acids contained in the neutral and polar lipids from Sprorthrix schenckii and Ceratocystis stenoceras and 3 mutants of the latter fungus were found to be identical. The major fatty acids were palmitic, oleic and linoleic. The fungi had similar quantitative composition especially the mutant strains and S. schenckii. This observation provides more data regarding the possible relationship between Ceratocystis and sporothrix.