Saline intrusion is threatening rice- and fish-farming households in the Mekong Delta of Vietnam. This study was conducted, based on interviews with 390 rice- and fish-farming households in An Giang, Can Tho, and Soc Trang—upstream, midstream, and downstream provinces, respectively—in the Mekong Delta, Vietnam. The results revealed that saltwater intensively intruded inland during the dry season and seriously affected rice- and fish-farming households. Not only the productivity of rice and fish was affected, but also household income, and the quality of natural resources and environment deteriorated. The fish-farming households faced the most serious effects and had fewer adaptation options compared to households undertaking farming with rice and integrated rice- and fish-farming. Households in all groups have developed adaptation options following the increasing degree of salinity, including: (1) changing their agricultural activity calendar, (2) using tolerant rice varieties and fish species, (3) changing cropping patterns and farming practices, (4) applying integrated production models, and (5) diversifying non-farming activities.