Objective: The study aimed to evaluate the homocysteine and cobalamin status of German vegans and determine whether the intake of very small amounts of foods of animal origin can improve this status. Design and setting: Cross-sectional study, Germany. Subjects: The dietary and nutritional intakes of 131 vegans (73 women, 58 men; age range: 20.2-82.1 years) were evaluated using a general questionnaire and two food-frequency questionnaires. Results: The prevalence of inadequate cobalamin status in volunteers of the German Vegan Study was 28.2%, and that of hyperhomocysteinaemia, 38.1%. Moderate vegans were affected to a lesser extent than were strict vegans. Duration of veganism and cobalamin concentration were inversely correlated (Spearman's r= - 0.175, P = 0.047). Folate concentration and erythrocyte aspartic acid aminotransferase activity were not correlated with plasma homocysteine concentration, but duration of veganism correlated positively with homocysteine concentration (Spearman's r= 0.319, P < 0.001). Cobalamin and homocysteine concentrations were inversely correlated (when controlling for duration of veganism; r= -0.602, P < 0.001). Conclusion: Cobalamin status needs to be improved in order to minimise the risk of hyperhomocysteinaemia.