The scientific literature was reviewed to identify obstacles and effective ways to improve primary care physician screening, interventions, and management of patient substance use disorders (SUDs). Major obstacles identified are physician lack of skills and self-efficacy in patient counseling, inadequate training at all levels of medical education, and lack of reimbursement and other health care systems support for services to patients. Physician abuse of drugs does not appear to be a major obstacle. Physician attitudes about patients with SUDS and the effectiveness of treatment services need to be addressed. Research points to the use of a multifaceted change strategy. Key components include practice-based training emphasizing screening and counseling skills throughout medical education, clinical systems to ensure regular SUD services (screening, intervention, and referral) to patients, and reimbursement and coverage systems to support physician interventions and patient services.