The treatment paradigm for advanced non-small-cell lung cancer has changed in recent years with the importance of histological subtyping for the choice of chemotherapy, and the use of molecular markers to select patients for targeted therapy. Maintenance therapy (MT) is another focus of interest. The potential benefit of MT for the patient is that it prolongs tumor control reached with first-line chemotherapy in order to improve overall survival with little added toxicity. Historical studies have never reached this goal, as the agents used for MT were too poorly tolerated. We review the data of the two types of recent MT studies, 'continuation' and 'switch' or 'consolidation' MT. We comment on how the benefits demonstrated in these studies may change clinical practice and reflect on factors that may identify subgroups of patients who derive the greatest benefit from MT in general, as this will help in a rational use of MT.