These study attempts analyze the chicken production scale in Battambang of Cambodian among the rural household rice farmers using Optimization Model. The study explains the explicit opportunity cost of not investing time and other reliable resources in the chicken (courtyard) production is the income the farmer would have gained competitively in the market price of chicken. The results suggest that two out of 6 districts have the potential to obtain optimal scale by increasing chicken head counts. High chicken death rate was detected in the region thus the authors suggests a subsidy policy for disease control should be provided to affected region or high risk region; and locally, there should be broader extension services orienting farmers on the proper management of small scale chicken production.