In general, the results indicated that authoritative parenting was negatively related to adolescent substance abuse, including all cigarette-related outcomes and most marijuana-related outcomes. Among the current sample, only monthly and lifetime marijuana use were found to be unrelated to authoritative parenting. Sensation seeking among adolescents was positively related to all marijuana outcomes, indicating that adolescents with high sensation-seeking tendencies had more favorable attitudes and intentions and used more marijuana than adolescents with low sensation seeking tendencies. The findings suggest that combining authoritative parenting with other protective factors may offset the risk of sensation seeking to substance abuse. Participants were 1,461 adolescents attending sixth through eighth grades in 7 public schools in central Colorado who were recruited to participate in a semester-long longitudinal study on the effects of cigarette ads on cigarette-related outcome variables. Participants completed pre- and posttests, which focused on any changes in cigarette- and marijuana-related outcomes due to the intervention. Following a baseline assessment, participants took part in a series of three computerized intervention sessions in which they were exposed to anti-cigarette and anti-marijuana ads embedded as commercials in a nationally syndicated situation comedy. The posttest was completed 3 weeks after the final intervention. Data were analyzed using hierarchical multiple regression models. Limitations of the study are discussed and include its use of self-report data from adolescents. Tables, references