It is possible to enhance the consumption of pro-health polyene fatty acids from an omega-3 group by adding them to some food products. Such a product is rapeseed oil. I can be naturally enriched using the above named components owing to its chemical affinity. Concentrated fish oil or flaxseed oil, a rich source of omega-3 fatty acids, can be used to enrich rapeseed oil. The objective of this analysis was to asses the effect of omega-3 fatty acids, contained in concentrated fish oil and flaxseed oil, on the oxidative and sensory changes in mixtures made of these two types of oil, when the omega-3 fatty acids are added to rapeseed oil. Samples of rapeseed oil enriched by the mixtures as described above underwent a special storage ability test. The samples were stored over 12 weeks, and during this period, peroxide (LOO) and anisidine (LA) values were measured. It was stated that at the beginning of storage, during a few weeks, the LOO value of the mixtures investigated increased, and, then, began to decrease. The decrease was mild, but progressing. It was also found that the higher the amount of omega-3 fatty acids in the mixture, the higher the decrease in the LOO value. This general tendency was the same for both the concentrated fish oil and the flaxseed oil, however, the LOO values of the rapeseed oil + concentrated fish oil mixtures were higher. The LOO value never exceeded a level of 5 milli-equivalents oxygen/kg oil, i.e. the maximum value of any refined rapeseed oil regarded fit for human consumption. The increase in LA of the studied mixtures containing concentrated fish oil was almost linear, and, it progressed along with adding the omega-3 fatty acids. As for the mixtures of rapeseed and flaxseed oils, the LA level remained constant or it insignificantly decreased when omega-3 fatty acids were added. When the storage-ability text was performed, the LA value increased in the mixtures containing both the concentrated fix oil and flaxseed oil; the increase continued over for weeks of storing the mixtures, up to the maximum level, and, after this period, it began to slowly decrease, and, it kept decreasing during the next weeks of storing the mixtures.