High school students (approximately 14-18 years old; N=2,568) completed questionnaires in which they reported on their involvement in substance use and delinquency, and their perceptions of parental warmth, control, monitoring, and knowledge. Three alternative models were compared describing the nature of relations among these variables. Problem behavior was best predicted by a model that included indirect effects of warmth, control, and monitoring (all by way of parental knowledge), as well as direct effects of control and monitoring. Analyses are framed and findings are discussed with reference to recent work by Stattin and Kerr (2000; Kerr & Stattin, 2000) on the measurement and meaning of parental monitoring.