This thesis is concerned with the comparing of sensory and analytical characteristic of red wines infected by Brettanomyces/Dekkera. For the purposes of the research twenty four samples of red wines were selected, that had been evidently affected by Brettanomyces/Dekkera yeasts. This yeast genus produces the volatile phenols linked to the distinctive aromas/sensory compounds in red wines characterised as being reminiscent of farmyards, animals or phenolic notes. The theoretical part covers the genesis and development of the infection in red wine, and how the sensory qualities of wine are affected by Brettanomyces/Dekkera yeasts. Possible causes of the infection and ways of preventing wines from becoming infected are discussed. The experimental part focuses on the analysis and statistical assessment comparation of the sensory evaluation resulst and the chemical analysis of volatile compounds results. The level of correlation between sensory perception of volatile phenols, which are linked to these undesirable aromas, and their real content was compared.