The rising use of cannabis and alcohol among young people in the United Kingdom has come under increasing public scrutiny in recent years and has been a great cause of concern among policymakers. Despite the mounting research literature in the area of adolescent drug abuse, relatively little is known about how parents respond to their children’s cannabis and alcohol use. The current study drew on qualitative interviews with 59 boys and girls aged 13 to 15 years to probe how young people perceived their parents responses to their cannabis and alcohol use. While some young people reported either prohibitive responses or passive tolerance responses by parents, another group of young people reported the open discussion and negotiation of boundaries regarding alcohol consumption. The approach to cannabis use was different and reflected an atmosphere of assumption and speculation rather than the open attitude toward discussion of alcohol use. The open approach to alcohol resulted in young people developing a reasonable approach to alcohol consumption. The findings suggest that steps should be taken to support parents in the open discussion of their children’s actual or potential cannabis use in order to reduce the harms associated with the drug’s misuse. Table, references