Abstract: The present study investigates the effectiveness of hypnosis in reducing mild essential hypertension. Thirty participants were randomly assigned to hypnosis (standardized, individual 8-session hypnosis treatment) or to a control group (no treatment). Results show that hypnosis is effective in reducing blood pressure in the short term but also in the middle and long terms. We did not find any relationship between the practice of self-hypnosis and the evolution of blood pressure or between anxiety, personality factors, and therapeutic results. The implications of the results of the psychological treatment of hypertension are discussed