Sonication technique has been commonly used in food industry, first of all in food preservation and food processing. The objective of this study was to assess the sonication as an alternative method to inactivate yeast cells. Additionally, it was considered whether or not the sonication could be used to obtain intracellular protein solution. Cells of Saccharomyces cerevisiae 2200 strain and a raw yeast biomass were sonicated in a 20 kHz horn-type sonicator. It was found that the time, duty cycle, and power of ultrasounds significantly impacted the cell inactivation and the protein extraction degree. The efficiency of extracting proteins from the cultured S. cerevisiae 2200 yeast strain amounted to 60 %, and from the raw baker’s yeast to 43 %. The disruption of yeast cells by ultrasounds can be a good laboratory technique used to permeabilize cell wall and to extract intracellular proteins. After sonication, the count of live yeast cells decreased by 100 to 1000 times compared to their initial count expressed as cfu/cm³; this effect can be intensified by combing the activity of ultrasounds with a thermal factor.