RESUMEN
<p><b>BACKGROUND</b>In grass-roots hospitals, the rate of misdiagnosis for lung cancer is rather high. The aim of this study is to investigate the reasons of misdiagnosis for lung cancer.</p><p><b>METHODS</b>A total of 31 patients with signs out of lung from 1987 to 2004 were analyzed retrospectively.</p><p><b>RESULTS</b>There were different degrees of misdiagnosis in these 31 patients. One half of misdiagnostic reasons were medical factors, and the other half were due to patients' carelessness (15 cases/16 cases, 48%/52%). The medical factors included lack of knowledge of medical workers about tumor and limited conditions in grass-roots hospitals. The patient factor was mainly that they did not receive medical treatment in time.</p><p><b>CONCLUSIONS</b>The key point of reducing the misdiagnostic rate of lung cancer is to improve the professional level of medical workers and popularize peoples' knowledge about lung cancer.</p>