Our aim was to analyze whether birth weight contributes to future hypertension through reduced kidney volume, and whether albuminuria could be a marker of this pathway. We included 103 patients with newly diagnosed essential hypertension and 92 normotensive controls. Blood pressure (BP) was measured using a mercury sphygmomanometer and a ABP monitor. Kidney volume was determined by ultrasound. Data on birth weight were obtained from mothers. Albuminuria was determined in 24-hour urine samples. Hypertensive patients had lower birth weight and higher albuminuria than normotensives. There was no difference in kidney volume between the two groups. We found a negative correlation between birth weight and systolic BP in the hypertensive group. BP was significantly correlated with BMI and albuminuria in the hypertensive group. Multiple regression analysis had shown the greatest impact of BMI on BP and had also demonstrated that 24-hour systolic BP showed the greatest risk for developing albuminuria in hypertensive patients. In conclusion, birth weight influences BP values in adult age, but it is not mediated by a reduced kidney volume. A strong correlation, independent of birth weight, was observed between albuminuria and BP values. Increased BMI is the most important independent risk factor responsible for BP increase, even in an early phase of essential hypertension.