 Over the past decade, many new programs intended to prevent substance use among adolescents have been developed and evaluated. There has been a recent shift towards brief interventions for youth in school Brown, 2001; DAmico and Fromme, 2002 and health care settings, such as emergency rooms and inpatient clinics Barnett et al., 2001; Colby et al., 1998; Monti et al., 1999. Although the primary care setting presents a unique opportunity to intervene with youth concerning drug use, such as marijuana or inhalants, many youth are not screened for use Friedman et al., 1990; Johnson and Millstein, 2003; Middleman et al., 1995 and preventive services in this setting are significantly below recommended levels Halpern-Felsher et al., 2000; Klein et al., 2001; Ozer et al., 2001. The objectives of the proposed research are to: 1 explore the feasibility of adapting a brief intervention from our previous work for use in the primary care PC setting, and 2 assess the short-term efficacy of the intervention in the PC setting. During year 1, focus groups of high-risk youth n16, parents n8, and providers n8 will provide feedback on barriers to implementing a substance use brief intervention in a PC setting. We define high-risk youth as those who may have already developed regular patterns of use or have experienced some problems due to their use. In addition, the intervention will be pilot tested with 10 high-risk youth who will provide feedback on intervention content. Revisions will be made to the intervention curriculum based on this feedback and in year 2, the short-term efficacy of the intervention will be tested with a small sample of high-risk youth n30. This study will extend brief intervention research for youth, as it will be one of the first to examine the feasibility of implementing a brief substance use intervention to PC with high-risk youth and to determine the impact of this intervention on short-term outcomes. 