Additive intercropping series of sunflower and basil were laid out under salty and fresh water irrigation management. The aim was to achieve the highest yield and intercropping advantage as a result of intercropping the two plants. An experiment was performed at Zabol University during two cropping years (2018 and 2019). Fresh water (ECe = 3.9 dS.m-1) and saline water (ECe = 1.1 dS.m-1) were taken from the Hirmand River and a local well, respectively. The irrigation water regimes were fresh water, salt water, and an alternating usage of salty and fresh irrigation water. In addition, five types of intercropping patterns were considered as sub-factors (100 percent sunflower (4 plants/m2), 100 percent basil (80 plants/m2), 100 percent sunflower + 50 percent basil, 50 percent sunflower + 100 percent basil and 100 percent sunflower + 100 percent basil. The results showed that the interaction between intercropping patterns and different irrigation regimes had a significant effect on 1000 seed weight, seed yield, harvest index, oil yield of sunflower, dry weight and essential oil yield of basil plants. In response to all irrigation regimes, the highest value of total land equivalent ratio (1.37-1.45) and intercropping advantage (0.29 - 0.48) occurred as a result of cultivating 50 percent sunflower + 100 percent basil, thereby appearing as a good model of intercropping. The results showed that intercropping patterns can be effective in modulating the negative effects of saline irrigation water on plant yield.