Adulteration of extra virgin olive oil (EVOO) with other vegetable oils is a common problem that occurs at today's olive oil world market. Hence, in this research the evaluation of method for lipid analysis MALDI-TOF/MS's effectivness has been investigated in order to detect adulterated EVOO. The research is based on the identification of triacylglycerols (TAG) which are specific for composition of EVOO, edible sunflower oil (S) and olive pomace oil (R). Analysis of MALDI-TOF/MS is conducted for the purpose of detecting adulterated EVOO with S and R in different ratios (1%, 10% i 20% w/w). The research of legally prescribed indicators K values has been conducted for determination of olive oil quality and adulterated EVOO detection. Results suggest that 1% addition of vegetable oils in EVOO can be noticed with MALDI-TOF/MS technology, although a performed statistical analysis was also necessary for its complete confirmation. Based on K270 value it was possible to detect addition of 10% S and R in EVOO, while ΔK value confirmed addition of 20% R in EVOO. Antioxidant capacity of all samples was determined by DPPH method and eastimation of total phenolic content was examined by Folin-Ciocalteu method. This was carried out to examine the impact of adulteration on oil antioxidant stability. Results suggest significantly higher antioxidant capacity and total phenolic content of EVOO in comparison to samples of R and S, while in oil mixtures was noted mild decrease in these parameters. Principal component analysis method (PCA) using mass spectrometry results of the main TAG present in oils, made possible to separate different category of oils and detect addition of 1% S and R in EVOO. This analysis discriminated EVOO from other samples and that confirmed the unique TAG of EVOO composition compared with other samples. Cluster analysis determined small distance among the cluster members (EVOO and oil mixtures) and significant distance between EVOO and other samples S and R.