Abstract.As yet, no distinct aetiological factor underlying hypertension in pregnancy has been disclosed, and there is therefore no clearcut treatment for this condition. The lack of well‐defined end‐points makes it difficult to plan and evaluate the results of studies on the treatment of hypertension during pregnancy. However, we cannot await the solution to the puzzle of pre‐eclampsia before providing treatment for this hypertension. Well‐designed investigations to determine the most effective form of such treatment are therefore of great value and must be carried out in spite of the many problems associated with these studies. If given due consideration, as discussed in this paper, this problem can be all