The present invention relates to methods for the production of .gamma.-linolenic acid (GLA) in oleaginous yeast. Thus, .DELTA.12 and .DELTA.6 desaturases able to catalyze the conversion of oleic acid to GLA have been introduced into the genome of Yarrowia, using zeta-directed integration. Transformed strains produced over 25% GLA in the total lipids, as opposed to wildtype Yarrowia that is unable to synthesize any GLA. Metabolic engineering and fermentation methods are provided to further enhance GLA productivity in oleaginous yeast.