Vegetables especially leafy ones are the major source of nitrite and nitrate in human diet.Because edible parts contain very high concentrations of nitrate that has been implicated in the occurrence of methaemoglobinemia and possibly in gastric cancer as well as other diseases,nitrate accumulation in plants is major concern,and is known to be a problem in most crops.The levels of nitrite and nitrate were evaluated in usable parts such as leaf and petiol of twenty four Iranian spinach (Spinacea oleracea L.) cultivars.The aim of this study was selection of the best cultivars for breeding programs and commercial production of spinach.