Squash yield and quality under furrow and trickle irrigation methods and their responses to different irrigation quantities were evaluated in 2010 spring and fall seasons. A field experiment was conducted using squash (Cucurbita pepo L.) grown in northern Egypt at Shibin El Kom, Menofia. A Randomized Split-Plot Design was projected with irrigation methods as main plots and different irrigation quantities randomly distributed within either furrow or trickle irrigation methods. Irrigation quantity was a ratio of crop evapotranspiration (ETc) as: 0.5, 0.75, 1.0, 1.25, and 1.5 ETc. Each treatment was repeated three times, two planting rows from five rows were left for squash seed production. In well-watered conditions (1.0ETc), seasonal water usable by squash was 304 and 344 mm over 93 days in spring and 238 and 272 mm over 101 days in fall under trickle and furrow irrigation methods, respectively. Squash fruit yield and quality were significantly affected by season and both irrigation method and quantity, except fruit number wasn't by irrigation method and its length wasn't affected by season. Interaction between season and irrigation quantity significantly affected leaf area index, TSS, and fruit weight. Moreover, seed yield and quality were significantly changed by season and both irrigation method and quantity, except harvest index wasn't affected by irrigation method. Only a significant interaction between season and irrigation method was for seed yield and 100 seeds weight. Interaction between season and irrigation quantity insignificantly affected seed yield and quality except harvest index. Both fruit and seed yields were significantly affected in a linear relationship (r2≥0.91) by either deficit or surplus irrigation quantities under both irrigation methods. Adequate irrigation quantity under trickle irrigation, relative to that of furrow, enhanced squash yield and improved its quality in both growing seasons. Fall season was not appropriate for seed production due to obtaining many of empty seeds caused by low weather parameters at the end of the season. The results from small experiment were extrapolated to big field to find out optimal irrigation scheduling under non-uniformity of irrigation application.