Physicochemical properties, sensory characteristics, and consumer acceptability of cookies produced with oat and barley powder were evaluated. Oat and barley powder was incorporated into cookie dough at 6 levels: oat : barley = 100:0 (S1), 80:20 (S2), 60:40 (S3), 40:60 (S4), 20:80 (S5), 0:100 (S6) and control. pH of the cookie dough was lowest in the S6 group and highest in the control, S1, S2, and S3 groups. There were no significant differences in density. The spread ratio and loss rate of cookies increased significantly with an increase in content of barley powder. The leavening rate of the S1 cookie group was the lowest. With regard to color, the a-values and b-values of cookies increased with a rise in content of oat powder, and the L-value increased with an increase in barley powder content. Analysis of cookie texture showed that hardness was highest in the S6 group with barley and lowest in the S1 group, but there was no significant difference between the control group and other experimental groups. In the sensory evaluation of cookies, there was no significant difference between the control and experimental groups in roasted nuttiness and sweetness. In overall acceptance of cookies, S6 was the least acceptable and S1, S2, and S3 were the most acceptable. Results suggest that oat powder is a suitable ingredient for increasing the functionality of cookies and consumer acceptability.