Etoposide is used commonly to treat both small cell lung cancer and non-small cell lung cancer. It is usually administered intravenously over 3 to 5 consecutive days, and usually given in combination with cisplatin. Preclinical cellular and clinical pharmacokinetic studies have demonstrated that etoposide is schedule-dependent and is optimally administered at low doses over prolonged periods of time. Recent early phase clinical trials have demonstrated that oral etoposide can be administered safely for 14 to 21 consecutive days. This schedule has demonstrated outstanding activity in patients with both recurrent and previously untreated small cell lung cancer. Activity against non-small cell lung cancer has also been reported; response rates are similar to those seen with the most active single agents used in the treatment of the disease. Chronic oral etoposide also has the advantages of outpatient convenience and tolerable side effects. This overview discusses the role of chronic oral etoposide in the management of small cell lung cancer and non-small cell lung cancer. The scientific rationale, results of early phase clinical trials, ongoing research, and future directions regarding the chronic administration of this important antineoplastic drug are also reviewed.