Stage IIB lung cancers according to TNM8 staging include T1-2N1M0 and T3N0M0 groups. It has been emphasized that the most important prognostic factor of lung cancer is of tumor in many studies. In this study, we investigated the prognostic effect of some variables including tumor diameter, visceral pleural invasion, lymph node invasion, type of surgery, etc. in same tumorstage. After the approval of the local ethics committee, a total of 139 patients who were surgically treated for non-small-cell lung cancer in our department and whose pathological staging was reported as stage IIB were included in the study. The 15 patients were female and 124 were male, and the mean age was 61.5 (Range, 39-81; SD, 7.9). The overall survival and disease-free survival of patients were analyzed according to N1 presence, tumor diameter, histopathological type, visceral pleural invasion, age, and gender. The 5-year survival rate was 50.4%, and the 5-year diseases free survival rate was 54.9%. The survival of N1 (+) group was worse than the T3 group. Pneumonectomy, big tumor diameter, and squamous cell carcinoma histopathology were negative prognostic factors for survival, whereas visceral pleural invasion and adenocarcinoma histopathology were found as statistically significant to negative effect disease-free survival. Furthermore the 5-year survival rate of T2bN1M0 group was found worst than others. According to the TNM system adopted in 2016, the stage IIB lung cancers are a heterogeneous group, and as the survival studies related to this group increase, a separate tumor stage formation or separation of T2bN1 group from stage IIB may be considered.