Flood defense (FD) projects are often evaluated from an engineering perspective in terms of flood frequency/flood risk assessment overlooking the productivity potential of the projects from an economic perspective. This is a limitation of the conventional assessment of flood defense projects that productivity potentials are not considered when they are evaluated. Although it is an established fact, FD projects affect the productivity of the production units/farms with them. Modified hydrological conditions of the production environments under the FD projects primarily bring about the changes in farm productivity. Hence, evaluation of FD projects without considering their productivity potential would provide a ‘partial assessment’ and it leaves room for polarization among stakeholders. This paper, however, addresses this limitation by evaluating FD projects form an economic perspective where productivity potentials of the FD schemes are taken into consideration. Two distinct indicators of productivity e.g., ‘technical efficiency’ and ‘yield-gap’ are used here. Stochastic Frontier Analysis (SFA) is engaged to estimate technical efficiency while a standard formula (developed by a synthesis between the ideas of ‘efficiency gap’ and ‘potential yield’) is used to measure yield-gap. This empirical study considers two contrasting FD projects, namely, the traditional flood defense (TFD) and the natural flood defense (NFD), implemented in the Southwest coastal zone of Bangladesh. These projects are evaluated with respect to rice production and the study results reveal that mean scores of technical efficiency for the TFD and NFD projects are respectively 0.78 and 0.76 while average yield-gaps are 719.18 and 807.33 in order. Again, ‘yield-gap ratio’ and the difference between the ‘potential yield increments’ are 1.12 and 2.84 respectively. These findings indicate that TFD project outperforms the NFD project marginally with respect to their productivity potentials. However, assessment of FD projects from engineering and economic perspectives provides a comprehensive evaluation which can resolve or at least attenuate the debate (if any) over the appropriateness of alternative projects and thereby prevents unnecessary delay in project implementation which has economic and policy implications.