We have investigated the effects of moderate global undernutrition during gestation in the rat on the blood pressure of male and female offspring, and on the development of systemic vascular function. Pregnant Wistar rats were nutritionally restricted (R) by feeding with 70% of the normal gestation-matched dietary intake from 0 to 18 days gestation.R offspring were growth retarded at birth but of similar weight to controls (C) at 20 days. Systolic and/or diastolic and mean arterial blood pressures, measured directly by femoral artery catheter, were elevated from 60 days onward in male R offspring (mean arterial pressure: day 60, P < 0.01; day 100, P < 0.05; day 200, P < 0.005, R vs. C), and from 100 days onward in female R offspring (mean arterial pressure day 100 and day 200, P < 0.05; R vs. C). Maximal constriction to phenylephrine (PE) (P < 0.05) and to noradrenaline (NA) (P < 0.05) was reduced in isolated femoral arteries of day 20 R pups. These differences did not persist into adulthood. In male adult R offspring (200 days), maximal vasoconstriction to the thromboxane A2 mimetic, U46619 (P < 0.05) and sensitivity to potassium (P < 0.01) were enhanced. Moderate maternal undernutrition in rat gestation adversely affects cardiovascular function in the offspring. These abnormalities increase with age and are more pronounced in males.