Cookies are one of the best-known quick snack products. Cookie production is currently limited to wheat and few cereal seeds in many countries. This study was conducted to investigate the possibility of producing cookies from blends of oat, fenugreek and wheat and to evaluate the supplementing effect of oat-fenugreek flour to wheat flour as well as baking temperature on the quality of cookies. Whole wheat, fenugreek and oat grains were, cleaned and milled into flour. The wheat, fenugreek and oat flours were blended using mixture de-optimal design to formulate composite flour with the ratio of 85%: 5%: 10%; 70%:10%:20% and 55%:15%:30%, respectively, whereas 150, 175 and 200°C temperatures were used for baking. The data generated were, statistically analyzed by one-way analysis of variance (ANOVA) using the SPSS software program (version 20). Grain quality, Functional properties and proximate analysis were carried out on the flour and cookies samples. The results indicated that the protein, fat, fiber, ash and energy values of the composite flours increased with the increase in blend proportion. The bulk density, WAC, OAC and foaming capacity were, observed to increase with an increase in oat and fenugreek proportion in the composite. The cookies made from supplemented flour resulted in significant increase in protein, fat, crude fiber and energy contents whereas carbohydrate content decreased significantly (P