Changes in oxytocin and cortisol levels were tested in healthy volunteers during hypnotic interactions in standardized laboratory sessions. Pre- to posthypnosis changes of oxytocin and cortisol were related to the hypnotic susceptibility of subjects and the relational experiences reposted by subjects and hypnotists on several paper-and-pencil tests. Results show that the changes in oxytocin are not related to hypnotic susceptibility but to relational experiences. After the hypnotic interaction, the subject's oxytocin level increased if perceived harmony with the hypnotist was high, whereas it increased in the hypnotist if the subject had memories of less warm emotional relationships with his or her parents. The results are interpreted within the social-psychobiological model of hypnosis.