This study explored sex offenders' parental and adult attachment difficulties and assessed the extent to which these were associated with preferences for therapists' interpersonal qualities. One-hundred and twelve adult male child sexual offenders were invited to provide selfreport data on their attachment histories, adult attachments and preferences for therapists' interpersonal qualities. A weak relationship between childhood and adulthood secure attachment was found, suggesting that attachment at the time of offending may be more relevant than childhood attachment to the aetiology of sexual offending. Participants valued a range of therapists' qualities previously identified as important for positive treatment change. Therapist trust and genuineness were perceived as particularly important by those with attachment difficulties, demonstrating the need for these qualities in offender programmes where attachment difficulties would be expected. There were some differences in the preferences for therapists' qualities between participants with different adult attachment types, highlighting the importance of responsivity factors in treatment.