The aim of the study was to determine of chosen chemical components in fresh macaroni summer squash after harvest and after storage as well as stabilized in dependence from irrigation and cultivar. Field experiments were carried out in the two successive vegetation seasons (2004 and 2005) at Kruszyn Krajeński near Bydgoszcz. Research material was eatable parts of fresh fruits, which were stored during six months in temperature 10°C and relative air humidity 85%, as well as marinade and frozen parts. Squash fruits after harvest from drip-irrigated plots were characterized by decreased content of dry matter, total sugars and reducing sugars as well as by increased content of vitamin C, carotenoids and β-carotin as compared to those harvested from non-irrigated plots. After storage, the content of dry matter was increased on average by 0,8%, and the reducing sugars content was slightly increased by 22,6%. The content of remaining components was significantly decreased. The vitamin C content decreased on average by 54% (lowest decrease in case of frozen material), the content of carotenoids and β-carotin decreased by 68%, the total sugar content decreased by 51% as compared to contents after harvest.