Due to the substantial protective effects of milk thistle to liver against various chemical compounds, a new healthy cereal product replacing wheat flour with milk thistle seed flour in the range of 5; 10; 15; 20; 25 and 30 % has been studied. As it has been found, milk thistle seed flour is a good source of total dietary fibre, proteins, mineral compounds and fats. During the experiments, effects of wheat flour replacement on technological properties of the dough were studied using Mixolab characteristics. From the results it can be stated that milk thistle seed flour replacement led to a decrease in water absorption and stability of dough. After baking, physical, mechanical, colour and sensorial properties of the biscuits were studied. The results have shown that even a 10 % replacement results in a significant difference at p < 0.05 in measured parameters compared to ones. However, it has been calculated that statistically insignificant replacement of wheat flour with milk thistle seed flour is up to 9.3 % with quality and sensorial parameters of the biscuits equal to those prepared from 100 % wheat flour. Thus, production of functional biscuits at these conditions is fully possible.