Subject of this thesis is to identify the nutritional risks of the vegan diet in adults, assess the risk severity and propose corrective measures, to alleviate the identified risks. Using the qualitative risk analysis method, individual nutrients were classified into three categories of risk severity, as low, medium and high-risk nutrients. Vitamins B12 and D were identified as high-risk nutrients, due to its absence in the non-fortified plant foods and regular supplementation is needed. Medium level of risk was assigned to the iron, calcium, iodine, zinc and omega 3 fatty acids. These nutrients can be obtained through the varied vegan diet, but for the different reasons, increased attention can be required. Subsequent SWOT analysis has identified also potential opportunities and threats of the vegan diet. The most important threats are connected to the high-risk nutrients and include anaemia and nerve disorders due to the vitamin B12 deficiency and increased risk of fractures due to the insufficient vitamin D intake. Well planned vegan diet has potential in prevention and treatment of the hearth disease and type 2 diabetes, cancer prevention, weight management and longevity. To obtain these benefits and prevent the major risks of the vegan diet it is mainly important to centre the diet mainly around the whole plant foods, including vegetables, fruits, whole grains, legumes, nuts and seeds, include reliable source of the iodine and regularly supplement vitamins B12 and D. Overall, well-planed vegan diet provides all essential nutrients and can bring important health benefits, but it is important to understand and respect its specifics.