The quality of parent–child relationships likely influences many decisions and behaviors made by early adolescents, including their alcohol and marijuana use. We examined how parent–youth relationship quality, parental monitoring, and parent substance use were associated with initiation of alcohol use, binge drinking, and marijuana use by 400 adolescents by the spring of 8th grade (ages 13–14), and changes in initiation through 9th grade (assessed 3 times; fall, winter, and spring). We measured both parent and adolescent report of parent–youth relationship quality and parental monitoring, expecting that both perspectives would uniquely contribute. Discrete Time Survival models showed that youth report of both a poorer parent–youth relationship and lower parental monitoring were associated with alcohol use, binge drinking, and marijuana use onset. Parent binge drinking also predicted youth alcohol onset and parent report of poor quality relationship predicted marijuana onset. Youth report of a poor relationship with parents was a stronger predictor for girls than boys on their alcohol use onset, and youth report of parental monitoring was more protective for girls than boys for both alcohol and marijuana use onset. Implications for preventing use of these substances during early and mid-adolescence are discussed.