Background: The impact on survival of thoracic complications secondary to bronchial carcinoma has not been clearly analyzed. Objectives: The purpose of this study was to assess the significance of these complications for the survival of lung cancer patients. Methods: All patients diagnosed at our center from March 2000 to January 2004 were analyzed to estimate survival among patients with or without thoracic complication. Any intrathoracic change or abnormality secondary to bronchial carcinoma such as atelectasis or pleural effusion was defined a thoracic complication. Survival was calculated using the Kaplan-Meier method, and the complications predicting survival were evaluated using Cox's regression analysis. Results: Of the 182 eligible patients, 61.5% had at least one thoracic complication. The complications were atelectasis, pulmonary metastases, pleural effusion, laryngeal nerve involvement, vena cava superior syndrome and others. Specific survival times for each complication were not different, except in the case of atelectasis. Median survival was significantly longer in patients with atelectasis, as opposed to nonatelectatic patients. Survival times in patients with at least one complication were not different than those of patients without complication. However, median survival of patients with one of the complications, excluding atelectasis (since this was associated with improved survival), was 3 months shorter (p=0.029). Cox's regression analysis also predicted atelectasis for improved survival. Conclusion: Atelectasis, which was determined to be the most frequent thoracic complication, was identified as a favorable prognostic factor in patients with advanced stage lung cancer. Copyright (C) 2005 S. Karger AG, Basel.