This present study attempts to examine the economic evaluation of rice-prawn gher farming system on land fertility for modern variety (MV) paddy production in Bangladesh. Laboratory based experimental data and field survey data were used in the present study. To test the change of land fertility, soils were collected before paddy production (after prawn production) and after paddy production (before prawn production) and tested in the Soil Resource Development Institute (SRDI) laboratory in Khulna, Bangladesh. The findings of the study indicate that the farmer applied comparatively less chemical fertilizers in MV paddy production under the rice-prawn gher farming system compared to MV paddy production. The input cost of chemical fertilizers for MV paddy farming was about six times higher than MV paddy production under the rice-prawn gher farming system. However, per acre MV paddy production of MV paddy farming was almost same to MV paddy production under the rice-prawn gher farming system. The rice-prawn gher farming is a cost-saving technology for MV paddy production.