This study was conducted to evaluate the effects of sweet pumpkin (Cucurbita Maxima D.) powder on the quality characteristics of cookies. The cookies were made with various sweet pumpkin powder levels (10%, 20%, and 30%). The pH of the dough increased while the density of the dough decreased as the amount of sweet pumpkin powder increased. The width of cookies determined by water content in dough increased with increasing sweet pumpkin powder level. The L value of cookies was significantly the largest in the control group. The b value was the highest for the 30% substituted sample group. According to textural measurements, the hardness, cohesiveness, springiness, and brittleness of the cookies with sweet pumpkin powder were higher in concentration than those of the control group. According to the sensory evaluation, the appearance, color, flavor, and texture of cookies with 10-20% sweet pumpkin powder were higher compared to those of the control group. The overall most acceptable cookie group was that with 10% added sweet pumpkin powder.