Lipid parameters (cholesterol CH, HDL-, LDL-cholesterol, triacylglycerols TG, atherogenic index AI) were estimated in four age groups of vegetarians, 82 males and 80 females, aged 15 to 60 years. The period of consumption of vegetarian food was 1.4 to 1.9 years for adolescents (15-18 years old) or 2.4 to 5.4 years for adults (age groups 19-29 years, 30-39 years and 40-60 years). Lacto-vegetarians constituted one half of females and one third of males. Vitamin C content, lipid peroxidation levels (conjugated dienes, CD) and the activities of catalase (CAT) and glutathione peroxidase (GSH-Px) were estimated in the oldest age group of males and females. Low levels of TG and glutathione peroxidase (GSH-Px) were estimated in the oldest age group of males and females. Low levels of TG and CH (in the lower half of the reference range), low calculated values of LDL-CH and AI, as well as values of HDL-CH in the upper region of the standard risk zone or over 1.4 mmol/l (reduced risk level) in males and females of all age groups are the positive factors of vegetarian nutrition in prevention of atherosclerosis. High levels of vitamin C in blood, absence of obesity and low blood pressure should be mentioned here as additional positive factors as well. When considered as a single isolated factor, the nearly significantly elevated values of CD (linked to increased intake of unsaturated fatty acids) could be a negative factor of vegetarian nutrition.(ABSTRACT TRUNCATED AT 250 WORDS)