This is a clinical practice guideline for patients with stage IV non-small cell lung cancer (NSCLC). Treatment options are compared including standard, histology, and platinum-based chemotherapy regimes, among others. Targeted chemotherapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is also discussed. Special topics of interest include the effectiveness of maintenance, second- and third-line treatments, as well as the treatment of elderly patients and patients with a poor performance status. Outcomes of interest include overall survival, progression free survival, response rate, toxicity, quality of life, and end of life.