Today, cancer is one of the diseases frequently occurring in individuals of all ages in the society with a high risk of death. In most types of cancer, traditional treatment methods can often be insufficient for many reasons. Cancer cells may gain resistance to chemotherapeutic agents, and chemotherapy may fail due to “Multidrug Resistance.” While the quality of the patient’s life decreases significantly during chemotherapy and/or radiotheraphy, the physician may become helpless with a treatment in which an adequate response cannot be obtained. Immunotherapy is not always an appropriate method or may be insufficient. There is a need for new approaches in an effective treatment. Thus, many research groups have focused on the site-specific delivery of active agents in nanoparticular drug delivery systems. What is expected from a versatile drug delivery system is that it provides rapid drug accumulation in the cancerous organ, bypasses first pass metabolism, exhibits improved drug therapeutic index with less systemic side effects, and provides anticancer activity against metastases. Lipid-based nanoparticular drug delivery systems, which are the focus of attention of many research groups due to their prominent properties, have an important place among these systems. In this chapterColloidal drug delivery systems, lipid-based nanoparticlesDrug delivery are reviewed considering their physicochemical characteristics and their targeting strategies. Due to the comprehensiveness of the subject, lung cancer, which is one of the most common and deadly cancer types in the world, has been reviewed as an example to reveal the potential of lipid-based nanoparticular drug delivery systems in cancer treatment. Valuable information gathered from recent scientific studies discussing their potential in the treatment of lung cancer is summarized.