In this study, clinical charts of 2,442 primary lung-cancer patients who were admitted to Kyushu University Hospital from 1987 to 2011 were reviewed retrospectively; 61.2% of all patients referred to our hospital presented with the appearance of various symptoms. The remaining 38.8% consisted of incidental discoveries resulting from health checkups (14.6%) and chest X-ray examinations for preexisting disorders (24.1%). Of all symptoms, fever, hemosputum, and breathlessness tended to make patients consult their primary-care doctors. On the other hand, appetite loss, nonproductive cough, and lumbago did not. Patients with lumbago, back pain, or hoarseness tended to consult more medical agencies before visiting our hospital, and 2.2% of all patients had ignored the first alert from a health-checkup agency, showing advanced-stage lung cancer on admission to our hospital. In this study, it is clear that some symptoms cause strong motivation to consult primary-care doctors, but some do not. It is important to widely inform patients of lung-cancer-associated symptoms, and these patients with suspected symptoms must be recommended to consult a medical agency without delay.