On the basis of neoclassical economic theory, the general purpose of this study is to undertake an estimation of a system of output supply and factor demand for intensive production system in the Mekong Delta, using a profit function approach. To achieve higher profits from rice production and efficiency of input use, farmers need to operate at the economic optimum rather than the technical optimum. Thus, this paper will explore whether or not farming households are efficient at their current level of inputs' application when input and output prices are taken into account.