Acanthosis Nigricans (AN) is a common finding in adolescents with obesity. Little is known about its relevance for cardiovascular (CVS) risk, in particular arterial stiffening. We investigated associations between AN, conventional markers of CVS risk and carotid-radial pulse wave velocity (PWV) in a community sample of adolescents with obesity aged 12-19 recruited to an obesity trial. AN was present in 63% of subjects and 43% had severe grading. Presence of AN and severe AN were associated with z-score of body mass index (BMIz). Presence of AN (but not severity) was associated with abnormal or fasting hyperinsulinaemia but not after adjustment for BMIz. PWV data were available for 147 (84% of participants). Severe-grade AN was associated with PWV (co-efficient 0.51, 95% CI 0.13-0.89, P = 0.01) but not when adjusted for BMIz, ethnic grouping and age. In our study presence and severity of AN offered little additional information on CVS risk beyond the degree of obesity itself. The relevance of AN for CVS risk should be interpreted with caution.