One of important characteristics of potato tubers, determining their functional value for consumption and processing, is enzymatic browning of raw parenchyma tissue. Stresses the potato tubers are exposed to during their vegetative season (drought, excessive precipitation, agrotechnical treatments, pathogens), harvest and transport (mechanical damage, bruising), and long-term storage are likely to deteriorate their quality, i.e. increase parenchyma susceptibility to darkening. Tubers tendency to darkening and post-damage spottening is a negative trait that limits or even disqualifies their usability as a raw material. A number of authors, including Rogozińska et al. [1986], Leszczyński [1994], Putz [1995], and Miller [1996], claim that the intensity of enzymatic browning – being to a considerable extent a genetically-modified trait – depends on the content of phenolic compounds and activity of polyphenolic oxidase in tubers. With access of oxygen, that enzyme oxidizes phenolic compounds occurring in a tuber (mainly an aromatic amino acid: tyrosine, and phenolic acids: chlorogenic, caffeic and others). Determination of such a significant characteristics as the susceptibility of tuber parenchyma to enzymatic browning may be carried out with various methods. One of them belong to rapid, cost-effective methods (visual), others require greater financial input and are more labor-consuming (colorimetric). The selection of an appropriate analytical method is crucial since it may determine agricultural product’s classification for feeding purposes only. Therefore, the study was aimed at comparing results of the degree of enzymatic browning of potato tubers determined with visual and colorimetric methods, as affected by herbicides applied, mechanical damages and storage.