In recent years, microorganisms play greater role in the production of industrially interesting substances. Fatty acids (FA) produced by microorganisms are widely used in the food and pharmaceutical industry and for production of alternative fuels. FA are an essential components of the membrane and storage lipids. Recent studies have shown that the yeast Saccharomyces cerevisiae is able to excrete FA in case of impared function of two genes, FAA1 and FAA4, which are involved in the activation of FA with coenzyme A. In our work we have tried to explain the relationship between excretion of FA and the capability of cells to store FA using a yeast quadruple mutant, QM (are1delta, are2delta, dga1delta and lro1delta) defective in storage lipid synthesis. We introduced a deletion of FAA1 and FAA4 in the wild type strain and QM strain. We have found that the FA excretion is affected by synthesis of triacylglycerols but not by synthesis of sterolesters. During the study of interconnection of storage lipids synthesis and FA excretion, we observed an increased synthesis of cis-vaccenic acid in QM cells. We have shown that it is a protection mechanism from toxicity of accummulating free FA in case the cell is not capable to store or excrete FA. By FA analysis of individual lipid classes in QM cells we found that cis-vaccenic acid persist predominantly in the form of free FA. By changing of cultivation temperature we have shown that it is possible to simply modulate the composition of excreted FA. Lowering the culture temperature (22 ° C) resulted an increased accumulation of unsaturated FA, whereas at a higher cultivation temperature (35 ° C) cells excreted in higher amounts saturated FA. By changing of the culture medium in form of low-cost growth substrate, molasses, we verified that yeast mutants preserved the ability to excrete FA in provided medium, which makes the process of FA excretion biotechnologically even more interesting.