Two field experiments were conducted under calcareous soil at Mariout Research Station, Alexandria Governorate during 2018/2019 and 2019/2020. Each experiment was arranged in split plot design with four replicates. The present study investigated the effect of naphthalene acetic acid (NAA) as plant growth regulator, applied as soaking on the yield, its components of yielded grains and quality of bread wheat cultivars under calcareous conditions. Moreover, the study aims to determine suitable concentration of NAA as exogenous treatment to enhance wheat cultivars tolerance to calcareous soils. Grain soaking with five levels of NAA, at (0, 5, 10, 15 and 20 ppm) on three wheat cultivars (Misr -1, Gemmiza- 11 and Giza- 169) and irrigated from artesian well water (1780 ppm). Obtained results showed that increasing of NAA from 5 up to 15 ppm, significantly increased all yield, yield components and protein contents in each growing seasons. Misr- 1 cultivar was superior to Gemmiza-11 and Giza-169, in both seasons.  NAA at 20 ppm was recorded as superior than 15 ppm for all yield criteria with Misr-1, in the two seasons.  It was observed that 20 ppm concentration of NAA showed better results in enhancing the straw and grain yields of the wheat cultivar, Misr-1 coinciding with producing high yield, yield attributes and protein content under Mariout Region, Egypt. Therefore, the application of NAA, at 20 ppm and Misr-1 on wheat under calcareous soils was more effective of yield, yield components and quality.