This paper describes a study of the degree of continuity in the drug treatment of hypertension. An analysis of antihypertensive drugs dispensed to 916 individuals during 1970-74 revealed that 22% of the men and 27% of the women were without treatment for 20-50% of their observation time. A closer examination of 46 patients under 60 years of age showed that between 2 and 20 physicians had been involved in the antihypertensive treatment of the individual patient. The time without treatment in this group of unselected patients varied between 0 and 77% of the observation time, the degree of discontinuity being insignificantly correlated to the resulting blood pressure level. Non-compliance was the cause for discontinuing a drug in at least every fifth case.