In the present study, human aortic heart valves from young donors were subjected to histopathological investigations. The presence of lipid deposits in the cusp base was shown in 42% of valves; the probability of lipid deposits occurring in 30-year-old donors was 36%. Cholesterol clefts were found in the cusp base in 24% of valves; the probability of cholesterol clefts occurring in 30-year-old donors was 21%. Microscopic study of heart valves demonstrated the presence of lipid deposits in subjects of an unexpectedly young age. Among the study material, 58% of valves obtained from donors aged 11-40 years were unsuitable for transplantation. Our results confirm the need for macroscopic inspection of heart valves before their being transplanted.