Purpose: The utilization of oilseeds in food formulations is prevalent due to their health benefits and nutritional value. These protein-rich oilseeds serve as an affordable and essential source of nutrients and bioactive compounds, fulfilling human protein requirements. As such, this study sought to investigate the impact of partially replacing wheat flour with oilseeds in different proportions on the nutritional and quality characteristics of biscuits. Design/methodology/approach: Oilseeds, including terebinth, sesame and flaxseed, were partially substituted with wheat flour in amounts of 0, 5, 10, 15, 20 and 25%. The effects of this substitution on the storage stability, nutritional content and physical properties of the resulting biscuits were examined. Findings: The L* (from 69.75 to 54.06) and b* (from 28.59 to 21.60) color values of biscuits decreased with the supplement of oilseeds. The oilseeds addition increased the protein, fat, energy, and ash values of biscuits. At the highest level of added terebinth, sesame and flaxseed, respectively, the amounts measured were 5984.62 mgGAE/kg, 1553.85 mgGAE/kg and 2169.23 mgGAE/kg, which were higher than the control biscuits (715.39 mgGAE/kg). The incorporation of oilseeds resulted in a substantial decrease in pH and peroxide values, while the moisture content was increased throughout the 6-month storage period. The use of terebinth in biscuits led to better oxidative stability than sesame and flaxseed-containing samples. The biscuit samples with terebinth had a longer induction time. The lowest induction time of biscuits with 25% flaxseed was chosen, approximately 3.5 h. Research limitations/implications: Oilseed flours, which are rich in lipids, have been shown to enhance the quality of biscuits. However, further studies could aim to reduce the amount of shortening used to improve their quality even further. Reducing the shortening could keep the lipid content at an acceptable amount, especially considering consumers' current expectations for low-fat foods. Practical implications: Plant-based bioactive are generally known as secondary metabolites and have promising therapeutic attributes, especially antioxidative properties. Social implications: Thanks to this composition, some of these seeds have proven effective in controlling and preventing metabolic diseases (hypertension, hypercholesterolemia, diabetes, coronary heart disease and several types of cancer) as well as providing interesting properties to foods. Originality/value: As result, oilseeds can be successfully used as functional and sustainable food ingredients to improve the functional, nutritional and storage stability of biscuits.