This study investigates the effects of incorporating dragon fruit peel powder (DPP) into cookies on their nutritional composition, microbial quality, and sensory properties. Two formulations were prepared: a control (DPP0) and a formulation with 5% DPP (DPP5). Nutritional analysis revealed significant improvements in ash (2.42±0.03% in DPP5 and 2.15±0.02% in DPP0), crude protein (7.69±0.14% in DPP5 and 6.75±0.02% in DPP0), crude fiber (0.82±0.08% in DPP5 and 0.09±0.02% in DPP0), and crude fat (27.63±0.04% in DPP5 and 26.63±0.02% in DPP0). Moisture content slightly decreased (4.50±0.14% in DPP5 and 4.78±0.21% in DPP0), and carbohydrate content was lower in DPP5 (56.94±0.03%) compared to DPP0 (59.60±0.19%). Over a 30-day storage period, the DPP5 cookies consistently showed lower microbial loads, starting from 0.5×10² CFU/g at day 5 to 1.9×10³ CFU/g at day 30, compared to DPP0, which ranged from 0.8×10² CFU/g to 2.2×10³ CFU/g over the same period. Sensory evaluation indicated a significant preference for DPP5 cookies, with mean scores for color (8.40±0.67), texture (8.28±0.55), odor (8.50±0.82), flavor (8.50±0.75), and overall acceptance (8.03±0.70), all surpassing those of the DPP0 cookies, which scored 7.25±0.63, 7.13±0.46, 7.05±0.68, 7.20±0.69, and 6.90±0.78, respectively. These results suggest that dragon fruit peel powder enhances the nutritional composition, microbial stability, and sensory appeal of cookies, making it a valuable ingredient for functional food development.