Resveratrol and other polyphenolic compounds are currently in the limelight all over the world due to their beneficial effects on the human body. This work describes the occurrence and determination of trans-resveratrol, cis-resveratrol and quercetin in various vegetables and fruits. An HPLC method with electrochemical detection is used for the determination. The concentrations of resveratrol were found to range from trace quantities up to 0.03 mg per g of dry weight of trans-resveratrol and 0.006 mg/g of cis-resveratrol. The highest known concentration was found in red cabbage and spinach, while a surprisingly low concentration was found in garlic. The quercetin content ranged from 0.003 mg/g to 5.9 mg/g. At the same time, we determined the total contents of polyphenolics and materials of the benzenediol type: their concentrations were found to range from 2 to 550 and from 0.005 to 6 mg/g, respectively.