The objective of the study was to determinate the effect of freezing and thawing methods, as well as of cryo-protective supplements added after 6 months of storage at -20 ºC on the durability of phenolic compounds and antioxidant capacity in fresh and freeze-stored strawberries. The content of total polyphenols and anthocyanins was compared in fresh and freeze-stored strawberries. Moreover, in thawed strawberries, their antioxidant capacity was determined. It was found that the highest content of polyphenols was in the fresh strawberries of Elkat cultivar (178.3 mg/100 g), and the highest anthocyanins content was in the Senga – Sengana cultivar (39.6 mg/100 g). After 6 months of freeze storage, the increase in the total polyphenols was reported (from 157.1 to 252.9 mg/100 g on average, depending on the experiment variant). The highest amount of polyphenols was determined in the samples with L-ascorbic acid added, and the lowest was in the samples with sugar and pectin added as cryo-protective substances (163.2 mg/100 g). After the storage, the content of anthocyanins significantly decreased (from 29.6 to 10.44 mg/100 g on average, depending on the experiment variant). The highest degradation of those compounds was found in the samples with L-ascorbic acid added (to 10.88 mg/100 g), whereas the lowest – in the control samples (to 39.09 mg/100 g). The strawberries with L-ascorbic acid added were characterized by the highest antioxidant capacity (2202.2 µM Trolox/100 g) and the samples with sugar and pectin added – by the lowest (252.4 µM Trolox/100 g). The accomplished study proved that the quick, liquid N2 freezing process impacted more satisfactorily the values of antioxidant capacity and the content of total polyphenols than the conventional freezing in a freezer, as did the quick thawing in microwave device compared to thawing at 20 ºC during a period of 20 hours.