Yarrowia lipolytica yeasts are a model species of oleaginous microorganisms capable of accumulating lipids inside the cell in an amount exceeding 20 % of dry matter. In addition to studies on how to increase the efficiency of oil biosynthesis, an important issue is, also, the selection of conditions for lipid extraction from yeast biomass. The objective of the research study was to assess the impact of some selected parameters (type of solvent, sample treatment method, and the duration of the process) on the yield of extraction, run in an Soxhlet extractor, of lipids contained in cells of wild strain of Y. lipolytica KKP 379 yeast, and on the composition of fatty acids in the microbial oil produced. The yeasts were cultured in a batch process, in a laboratory bioreactor in a rich YPO medium, as well as in nitrogen restricted mineral media; thus, it was possible to obtain a cell biomass with varying contents of microbial oil. In the research, Latin Square Designs were applied so that the effect of biomass treatment method could be unmasked on the dependent variable, i.e. the content of lipids in the yeast biomass. The best results were achieved when the biomass was prepared using a commercial preparation of Y-PER. The applied duration time of extraction and the used type of solvent (petroleum ether or hexane) did not significantly impact the process yield. However, the type of solvent impacted the content of three fatty acids of the fourteen identified in the lipids extracted from the yeast biomass, ie. the content of palmitoleic, eicosapentaenoic, and docosatetraenoic acids. Higher contents of the above mentioned compounds were determined in the hexane extracted samples.