The main aim of this research is to improve the squash yield and quality using sulphur and pozzolan as soil conditioners in Saudi Arabia. This experiment conducted during winter and spring (2012 and 2013). A split split plot design with 3 irrigation water salinity levels (IWSL) (1200, 3000, and 6000 mg/l), 4 pozzolan placements (PP) (surface, 10 cm depth, 20 cm depth, and control), 3 sulphur doses (SD) (0, 4, 6 ton/ha), and 3 treatments was used. Applied PP in the soil surface and SD 6 ton/ha under IWSL 1200 mg/l increased plant height (77.57 and 72.80%) number of leaves/plant (38.21 and 31.45 leaves), fruit setting (42.54 and 40.24%), fruit yield (23.17 and 20.53 ton/ha), and water use efficiency (294.90 and 258.79 kg/mm/ha) respectively in the winter and spring compared with the control (no pozzolan, no sulphur and IWSL 6000 mg/l).