To evaluate the efficacy and toxicity of a brief, intensive cisplatin-based outpatient chemotherapy regimen with filgrastim and megestrol acetate support for patients with stage IIIB and IV non-small cell lung cancer (NSCLC) and a favorable performance status. Thirty patients with no prior chemotherapy were enrolled in this phase II protocol. Patients received cisplatin 50 mg/m2, ifosfamide 2 g/m2, mesna, and a 7-day course of oral etoposide beginning on days 1, 15, 29, 43. and 57 for a total treatment duration of 10 weeks. Filgrastim was administered for 7 days after each course of oral etoposide. Megestrol acetate 250 mg PO was administered throughout the duration of chemotherapy. Thirty patients were evaluable for toxicity and 27 for response. Among those evaluable for response, partial remission occurred in 11 (41%) patients, and median survival was 10.5 months. Nadir neutrophil count of < 500/mm3 occurred in 19 (63%) patients. Weight loss occurred in only nine patients (median 3.4 kg, range 1.6-7.3). There was no difference between pre- and post-treatment weights (P=0.35). Two patients developed pulmonary embolism. Grade 3 or 4 non-hematologic toxicity occurred infrequently. This regimen appears to be similar in efficacy to the most active regimens reported by other investigators. Innovative features of the regimen include the brief treatment duration, the use of serial 7-day courses of filgrastim to facilitate weekly chemotherapy treatments, and the use of megestrol acetate to minimize constitutional symptoms. However the use of megestrol acetate in this setting may be associated with an increased risk of thromboembolic complications. This may provide a model for other palliative regimens specifically designed for patients with a favorable performance status and advanced NSCLC.