Our objective was to compare the blood pressure of 20-y-old very low birth weight (VLBW; <1.5 kg) individuals with that of normal birth weight (NBW) control individuals. The population included 195 VLBW (92 female and 103 male) and 208 NBW (107 female and 101 male) individuals who were born between 1977 and 1979. Independent effects of birth weight status (VLBW versus NBW) and within the VLBW cohort of intrauterine growth (birth weight z score) were examined via multiple regression analyses. VLBW individuals had a higher mean systolic blood pressure (SBP) than NBW control individuals (114 +/- 11 versus 112 +/- 13 mm Hg). SBP for VLBW female infants was 110 +/- 9 versus NBW 107 +/- 12 and for VLBW male individuals was 118 +/- 11 versus NBW 117 +/- 11 mm Hg. After adjustment for gender, race, and maternal education, the difference in SBP between VLBW and NBW individuals was 1.9 mm Hg but was 3.5 mm after also adjustment for later size (20-y weight and height z scores), which reflects catch-up growth. For female individuals, the difference in SBP between VLBW and NBW individuals was significant both unadjusted and adjusted for later size, whereas for male individuals, the difference was significant only after adjustment for later size. Intrauterine growth did not have a significant effect on SBP within the VLBW group, even after adjustment for later size. VLBW individuals, specifically female individuals, have a higher SBP than NBW control individuals. This is not explained by intrauterine growth failure.