The research aimed to estimate the optimal sizes for both production and areas planted with cowpea crop in Al-Hawija district for the 2023 production season for a random sample that included 25 farms out of the total farms in the study area. The cost function was estimated in its cubic form to pass the statistical, standard and economic tests using the statistical program (SPSS25). The results of the estimated model showed that the optimal size of production reached (1.914) tons/dunum and the optimal areas of the crop reached (2.359) dunums, which is larger than the actual sizes in the research sample. The same applies to the value of the total revenue and profit, which amounted to (3829856) and (3829712) thousand dinars, respectively. The economic efficiency of the cultivated areas reached about 55% and the production quantity reached about 62%. This percentage is somewhat low due to the tendency of farmers to cultivate more profitable crops. The research recommended the necessity of motivating farmers in how to use resources optimally and the possibility of using Modern techniques in agriculture through the use of improved seeds with high productivity and disease resistance, as well as modern irrigation techniques to reduce waste in the amount of water used, thus enabling the possibility of reaching the optimal volumes and achieving levels of economic efficiency by activating the advisory role in this regard and holding advisory seminars.