Blood pressure (BP) levels were studied in 524 youth ages 4–19.9 years who reside in Samoa. The data were collected in two separate cross-sectional samples taken in 1979 (n = 292) and in 1991–93 (n = 232). BP was compared between these two study samples to evaluate the temporal change in BP among youth in response to the processes of economic modernization in Samoa, and specifically on how temporal increases in body size influenced BP levels. Proportions of youth with elevated BP levels were estimated using the Second Task Force criteria. In males and females 10–19 years, age-adjusted systolic BP was significantly higher in the 1991–93 sample than in the 1979 sample, and the difference became insignificant after adjustment for body mass index. The proportion of those ages 10–19 years with elevated BP ranged from 11–15% in the 1979 study sample and was ∼25% in the 1991–93 study sample. There appears to be a temporal trend of increasing adiposity and BP in those 10–19 years and the BP differences are attributable to the higher levels of adiposity. Am. J. Hum. Biol. 16:158–167, 2004. © 2004 Wiley-Liss, Inc.