This study examined the effects of preliminary contact by mail and telephone on the rate of response to a follow-up survey offormer mental health patients. The subjects were the par ents or parenting figures of 145 children due for six- or eighteen-month follow-up as part of the evaluation of the services provided at an outpatient child psychiatric facility. The survey instruments were the Child Behavior Checklist and a thirty-one item descriptive adjective rating scale. A significant effect wasfoundfor the use of preliminary contact, but notfor the use of telephone contact rather than mailed precontact. Additionally, it wasfound that it was difficult to contact subjects over the telephone and that telephone precontact was more expensive than mailed precontact. This article also addresses the problem of maintaining patient confidentiality while identifying prospective subjects who had moved since their last visit to the facility for treatment. This balance between study power and former patients’ rights to privacy is a difficult question for mental health service evaluations.