A thorough behavioral diagnosis of why parents do and do not use car safety seats is important for designing an effective, comprehensive approach to the significant public health problem of childhood motor vehicle occupant deaths and injuries. With a clear understanding of the demographic, knowledge, attitudinal and social support factors related to car seat use, it will be possible to develop or refine program methods and persuasive communication strategies which will have the greatest potential for effectiveness. Project KISS (Kids in Safety Seats) of the Maryland Department of Health and Mental Hygiene surveyed parents of young children in Maryland to identify factors which differentiate child restraint device users from nonusers. A statewide telephone survey was conducted using random digit dialing, a method of computerized sampling for telephone interviewing. The survey instrument incorporated demographic variables and used Fishbein and Ajzen's model of behavioral intention to develop an attitude scale and identify social referents important to parental safety seat use. Of the factors associated with reported use of car seats, the attitudinal variables were extremely significant. Using these variables as well as spouse approval, socio-demographic characteristics, and other preventive health behaviors of parents, resulted in the correct classification of 75.5% of cases and 26.7% of the variance in reported car seat use. Practitioners can use this analysis to design and target effective educational efforts to those individuals who are least likely to use car seats properly and consistently.