Effects of additions of buckwheat flour and sourdough on the total phenols content, antioxidant activity, and sensory properties of crackers were examined. Different mixtures of wheat flour with addition of buckwheat flour and sourdough were used for the prepartion of crackers. Two types of lactic acid bacteria (Lactobacillus plantarum and Lactobacillus brevis) were used for the preparation of buckwheat sourdough. Properties of crackers made with addition of buckwheat flour and sourdough were analysed in comparison to control crackers made only with wheat flour. Significant increase of total phenols in comparison to wheat flour dough (0.73 mg gallic acid equivalent (GA)/g of dry basis (d.b.)) was accomplished by adding buckwheat flour (1.12 mg GA/g d.b.) and sourdough (1.77 and 1.79 mg GA/g d.b.) regardless of the type of lactic acid bacteries used. All samples showed the decrease in total phenol content during baking process. Crackers with sourdough had higher antioxidant activity (16.84 and 15.84 mmol Fe3+/g d.b.) compared to crackers made with addition of buckwheat flour (10.42 mmol Fe3+/g d.b.) and control sample (7.76 mmol Fe3+/g d.b.). The result of sensory analysis showed positive influence of sourdough on taste and texture of crackers and insignificant differences in odour and appearance of tested samples. Also, the chewiness of crackers made with the addition of buckwheat flour and sourdough was improved compared to control crackers made from wheat flour.