The aim of this work was to determine vitamin contents in spinach produced by different cultivation type (organic and traditional), harvesting period and after cooking in water. The determination was carried out by High Performance Liquid Chromatography. There was no significant difference in folate contents between spinach cultivated by traditional and organic method and there was also no significant difference between the values obtained at different periods of the year. Folate levels determined as 5-methylTHF and 5-formylTHF varied from 226 to 527 microg/100 g and 4.6 to 10 microg/100 g, respectively. Cooking in water resulted in approximately 74% of losses of 5-methylTHF and 56% of 5-formylTHF. The mainly losses occurred by leaching.