In order to study the effect of nano fertilizer on growth of potatoes plants grown and pests infestations under salinity condition, a pot experiment conducted in the greenhouse of the National Research Centre, Dokki, Cairo, Egypt. The treatments were as follows: Salinity, irrigation by diluted sea water in the concentration of 2000 and 4000 ppm more than the tap water as a control. Nitrogen nano fertilizer sprayed in the rate of 100 and 200 ppm more than the distilled water as a control. A negative relationship was detected between salinity levels and stem, leaves and top dry weight and pests' infestations. The same relation also found for stem, leaves and top fresh weight. This data showed that showed that the nano fertilizer in the rate of increased the fresh weight by 3-fold compare to the control plants. The dry mass of leaves, stem or top weight treated with nano fertilizer improved by about 1.5-fold than that received distilled water. In spite of the decrement in plant height, fresh and dry weight of potatoes plants but on reverse, the nano fertilizer spraying increased these parameters. The improvement caused in growth characters as result of nano element was true under different levels of salt stress. The nano fertilizers significantly decreased the insect pests infestations under laboratory conditions. Results showed that under field conditions the yield significantly increased during season 2021 and 2022 after the nano fertilizers applications.