Research background. In spite of being a significantly growing segment, there still exist problems regarding the nutritional, technological and sensory profiles of gluten-free products. Thus, the combination of a variety of functional ingredients is required in order to achieve the desired product quality. Experimental approach. Flours of chestnut, buckwheat and potato were chosen in this study because they are all gluten-free; nutritionally richer and technologically more advantageous compared to wheat flour. They are applied together with chia seeds, which are also functional ingredients, due to being rich in dietary fiber and unsaturated fatty acids. Therefore, this study aims to evaluate the utilization of chia seeds with chestnut flour, buckwheat flour and potato flour in biscuits as overall quality enhancers in gluten-free products. The proximate composition, total phenolic content, antioxidant activity, some biscuit quality parameters and the sensory properties of the samples were investigated and some changes in these products during storage were monitored and evaluated. Results and conclusions. According to the results, biscuits with chestnut flour had the highest phenolic content (400.2 mg GAE/100 g dry sample) and total antioxidant activity (155.5 mg Trolox equivalent (TE)/100 g dry sample). Biscuits with chestnut and chia seeds had the hardness of 30.1 N (p<0.05). In addition, the use of chia seeds significantly increased the overall acceptability and flavor scores according to the sensory analysis results. During storage, chia seeds affected the oxidation stability, however the fatty acid profile stayed almost unchanged except for the losses in lauric acid, stearic acid and α-linolenic acid (p<0.05). In conclusion, the biscuits with chestnut and chia seeds were more prominent, with remarkably better nutritional characteristics and sensory attributes. Novelty and scientific contribution. The study fulfills a need for the growing gluten-free market by incorporating the functional nutrients of chia seeds, chestnut flour and buckwheat flours together to achieve the production of nutritionally improved and organoleptically acceptable gluten-free biscuits. Furthermore, this study makes an overall evaluation of the changes in product quality during storage to provide new ideas for an overall innovation in the gluten-free foods market.