ABSTRACT.In the years 1969 — 1973, 0.3% of 17000 unselected non‐diabetic pregnancies were complicated by severe pre‐eclampsia, 0.6% by mild pre‐eclampsia and 0.6% by hypertension in pregnancy. Records from affiliated maternity centers and the hospital were studied for these 261 women and for 260 women with matched normotensive pregnancies.The women with pre‐eclampsia/hypertension in pregnancy had higher blood pressure than the control group very early in pregnancy. The hypertensive women were more often primiparous and they had a slightly higher body weight. The patients with severe pre‐eclampsia were older than the other women (30.4 vs 25.4 years for controls, p<0.001). Immigrants were not more commonly found in the hypertensive groups, but unmarried mothers were more often seen in the mild preeclampsia and pregnancy hypertension groups, 19.1% and 20.6% respectively compared to 7.7% in the control group (p<0.01). A family history of hypertension was frequently reported in all groups.The most striking characteristic of women with pre‐eclampsia/hypertension in pregnancy was their elevated blood pressure before or very early