Primary care physicians are more likely to see patients with depression than with any other disorder except hypertension, and its management poses a challenge to busy primary care practices. The Patient Health Questionnaire-9, a simple self-administered tool of proven validity and reliability, is a commonly used screening instrument for depression in primary care practice. This review article provides a system-based approach to depression management using the Patient Health Questionnaire-9 to guide clinicians in the identification and treatment of depression and its follow-up care.