The aim of this study was to analyze the information needs of lung cancer patients from diagnosis until first treatment follow-up. Sixty-nine participants with lung cancer were recruited from Ditmanson Medical Foundation Chia-Yi Christian Hospital in Midwest Taiwan. The Modified Toronto Informational Needs Questionnaire (TINQ) was used to assess information needs during visits to the outpatient oncology department. Generalized estimating equations were applied to compare changes in information needs over time and to examine correlates of information needs of lung cancer patients. The greatest concern of lung cancer patients was the cancer itself and access to recovery information. The need for information regarding food selection and social welfare resources was also high. However, the means of information needs for each domain significantly decreased over time. Demographic information (age, gender, disease stage, current treatment, education, work status, and having children) was significantly associated with information needs over time. The need for “disease-related information” remained high regardless of disease stage. Oncology nurses can use the results of this study to better address the information needs of patients in an effort to fill knowledge gaps between patients and healthcare providers. Further studies are needed to explore the use of an appropriate instrument, like that used in this study, to identify newly-diagnosed lung cancer patients’ difficulties, concerns, and target interventions to improve their quality of life.