Fish can be regarded as a promising protein ingredient for food fortification and enrichment. This study aimed to investigate the potential application of Nile tilapia fish as a dietary supplement. Fish powder was fortified in 0 (control), 5, 10 and 15% levels in dry ingredients by replacing wheat flour and other ingredients were kept constant. Then, biscuits were prepared and the proximate composition, physical and texture properties were determined, as well as sensory acceptance. The addition of fish had a statistically significant effect on moisture, ash, fat, protein, carbohydrate, total energy, color, water activity, hardness and sensory acceptance. The protein content increased as much as 2.4-4.6 times as more fish was added. Results show that up to 5% fortification level, the biscuits were acceptable with improved functional properties compared to the control. There were significant changes in physical transformation in the biscuits packaged with polyethylene and aluminum foil at 25°C and 35°C, respectively. Fortification of fish powder could be used in the production of high-protein biscuits.