The objective of the analysis was to evaluate the chemical composition of plant oils with high content of linolenic acids, especially the composition of polyenic fatty acids, as well as of other components that appear important from the point of view of their dietary value and oxidative stability. The material analyzed constituted the following plant oils: four cold pressed oil types (made from flax, camelina, borage, and echium) and one type of refined oil (made from blackcurrant seeds). The determined parameters were the content and composition of fatty acids, tocopherols, sterols, and the content of pigments, Fe, and Cu. The oils analyzed were characterized by a particularly high content of α-linolenic acid (flax, camelina, echium), γ-linolenic acid (borage), and stearidonic acid (echium). Some of them were found to be a good source of tocopherols (blackcurrant seed oil); but the quantity of phytosterols in them was not significant. In the cold pressed oil types, it was reported an increased content of chlorophylls pigments and of Fe. A significant quantity of n-3 fatty acids (α–linolenic and stearidonic) and also of γ–linolenic acid in the examined oil types indicates their exceptionally high dietary and healthful values. However, the high degree of non-saturation and the increased level of chlorophylls and Fe may be the factors to negatively impact their oxidative stability.