Hypertension and obesity are serious health burdens in sub-Saharan Africa. Urbanized Africans seem to be more susceptible to the development of these diseases than Caucasians. Current research suggests that leptin may be an important contributor to the development of hypertension and atherosclerosis. The aim of this study was to investigate leptin levels and their associations with cardiovascular function in urbanized Africans and Caucasians. Serum leptin, ambulatory blood pressure and carotid intima-media thickness were measured, and the cross-sectional wall area (CSWA) was calculated. The results showed that Africans had higher leptin levels (P<0.001), ambulatory blood pressure (P<0.001), carotid intima-media thickness (P<0.01) and CSWA (P<0.01) than Caucasians. As we found no interaction between ethnicity and gender for the association between leptin and the cardiovascular variables, we focused mainly on the total group of Africans and Caucasians. In single, partial and multiple regression analyses, positive associations of ambulatory systolic blood pressure (β=0.256; P<0.001), diastolic blood pressure (β=0.143; P=0.012), pulse pressure (β=0.327; P<0.001) and CSWA (β=0.107; P=0.038) with leptin were observed. Even after adjusting for body mass index (BMI), the association between CSWA (β=0.107; P=0.038) and leptin remained. Our findings therefore suggest that leptin may contribute to the development of atherosclerosis, independent of BMI.